Module 8
TABLE OF CONTENTS
Chapter -1
Diet, nutrition, physical activity and body fatness
Genetic damage and cancer
Body fatness and the hallmarks of cancer
Dietary exposures and the hallmarks of cancer
Recommendations for Cancer Prevention
Why is it important to eat well when you have cancer?
What is a balanced diet?
The food pyramid
What is a serving?
Eating and cooking tips
What is a healthy weight?
How do I know if I’m a healthy weight?
Nutrition and treatment
Surgery
Chemotherapy.
Radiotherapy
Biological therapy
Hormone therapy
Tube feeding
Feeding into a vein
Eating problems during treatment
Healthy lifestyle and cancer prevention
Cancer is a Multistep Progressive Disease Process
Currently Recommended Cancer Nutrition and Physical Activity Preventive Measures_
Importance of Healthy Body Weight Throughout Life
Physical Activity and Cancer Prevention
Healthy Lifestyle and Cancer Prevention
Vegetables and Fruit: BAFCS
Role of energy Intake
Biological Mechanisms of Cancer Preventive Activity
Oxidative Stress
Insulin-IGF Hypothesis
➤Diet, nutrition, physical activity and body fatness
Nutrition is the set of integrated processes by which cells, tissues, organs and indeed a whole
organism acquire the energy and nutrients needed to function normally and have a normal structure.
Nutrition is important throughout life, allowing an organism to grow, develop and function according
to the template defined by the genetic code in the organism’s DNA. Ultimately, all the energy and
nutrients needed for the life-sustaining biochemical reactions that take place in an organism for
metabolism come from the diet. Some, known as essential nutrients, must be consumed ready
made; the body can synthesise others from various components of the diet. The diet also contains
many substances that are not nutrients (not necessary for metabolism) but can nevertheless
influence metabolic processes. These include common chemicals such as phytochemicals, dietary
fibre and caffeine, as well as some harmful substances such as arsenic Physical activity is any
movement using skeletal muscle. It is more than just exercise; it also includes everyday activities
such as standing, walking, domestic work and even fidgeting. Appropriate physical activity creates a
metabolic environment in the body that reduces susceptibility to some cancers. The amount and type
of physical activity can influence the body’s overall metabolic state, as well as total requirements for
energy, which in turn can impact on the amount of food (and nutrients) that can be consumed without
storing excess energy as fat. Excess energy intake that is not balanced by physical activity leads to
positive energy balance and ultimately weight gain and higher body fatness. When we talk about
nutrition in this report this includes body composition which encompasses body fatness.
➤ Genetic damage and cancer
The rogue capabilities of cancer cells generally result from the accumulation of genetic damage – to
cells’ DNA over time. This damage tends to involve multiple mutations and epigenetic changes.
Mutations are permanent changes to the DNA sequence, which are inherited by daughter cells when
cells divide. Epigenetic changes affect the structure of DNA in other ways (for example, extra methyl
groups may be added). These changes, while reversible, can still be passed on when cells divide.
Mutations can have potentially beneficial effects, which underpins the possibility of evolution by
natural selection. Some are neutral. Others, like those linked to cancer, are harmful. A mutation may
lead to the production of a protein that functions abnormally, or not at all, or to changes in the amount
of protein that is produced – including the complete failure of a gene to produce a protein. Normal
cells use epigenetic modifications to regulate gene expression to control which genes are turned on
and off. Patterns of gene expression are crucial to determining the structure of all cells, and how they
behave. Control over the pattern of gene expression enables the capabilities of cells to change over
time during early development and allows cells to specialise. Although all healthy cells within an
organism carry the same genetic code in their DNA, specialised cells have a unique appearance and
set of capabilities because they have a particular set of functioning genes, controlled by epigenetic
influences. Both the genetic and epigenetic changes that cancer cells accumulate can alter gene
expression (see below) in ways that enable the cells to acquire the capabilities known as the
hallmarks of cancer.
Diagram
Cells of the tumour microenvironment
Diagram
Most solid tumours contain a range of distinct cell types and subtypes that collectively enable tumour
growth and progression. The abundance, spatial organisation and functional characteristics of these
multiple cell types, and the make-up of the extracellular matrix, change during progression to create a
succession of different tumour microenvironments. Thus, the core of the primary tumour
microenvironment differs from microenvironments seen in tumours that are invading normal tissue
and in metastatic tumours that are colonising distant tissues. The premalignant stages in
tumorigenesis also have distinctive microenvironments. The normal cells that surround the primary
and metastatic tumour sites probably also affect the character of the various tumour
microenvironments.
1. Cancer develops from rogue cells, with genetic changes, that acquire capabilities known
as the “hallmarks of cancer
There are several hundred types of cancer, arising from different tissues. Even tumours arising from
the same tissue are increasingly recognised as comprising several different subtypes. What
characterises cancer is a shared constellation of abnormal cell behaviours, such as rapid cell division
and invasion of surrounding tissue, which are linked to changes in DNA. Cancer develops when the
normal processes that control cell behaviour fail and a rogue cell becomes the progenitor of a group
of cells that share its abnormal behaviours or capabilities. This generally results from accumulation of
genetic damage in cells over time. The cancer cell is a critical part of a tumour but only one of several
important types of cell that create the tumour microenvironment.
Although a bewildering variety of possible genetic changes can combine to cause cancer, the range of
abnormal capabilities that cancer cells share is much narrower. These capabilities are known as the
‘hallmarks of cancer.
Sometimes one or more of the genetic factors that contribute to the development of cancer is
inherited. Such familial cancers are uncommon (playing a role in 5 to 10 per cent of all cancers), but it
is important to identify them so that personalised preventive strategies can be offered to carriers and
their families.
Diagram
Despite the multitude of pathways through which genetic damage can lead to the development of
cancer, almost all solid tumours can be characterised by a relatively small number of phenotypic
functional abnormalities. These eight hallmarks of cancer are facilitated by two enabling
characteristics, genome instability and mutation, and tumour-promoting inflammation.
Diagram
The hallmarks of cancer represented on the right are functional abnormalities characteristic of cancer
cells, which can be related to the pathophysiological stages of cancer development, represented on
the left.
2. The rogue capabilities of cancer involve dysregulated activities of normal cells
The rogue capabilities of cancer cells, which can be harmful to an organism, are not all unique to
cancer. They are actually beneficial to some normal cells at certain times. As an organism develops
from a fertilised egg during embryonic and fetal life, its cells display a range of behaviours that are
appropriate to each stage of development, but which tend to lie dormant at other times. These
include capabilities that are typical of cancer cells, such as rapid cell division and invasion of
surrounding tissues. Inappropriate and untimely activation of such capabilities in cells of an adult
organism can mean those cells behave in the way that defines cancer. This can happen if the genetic
changes that accumulate in cancer cells affect which genes are turned on or off. One way of thinking
about cancer, therefore, is that it is the inappropriate and abnormal resurrection of capabilities
needed by cells during normal development after fertilisation.
3. Almost all cells are vulnerable to the genetic damage that causes cancer
Almost all cells in an organism are vulnerable to damage to their DNA. For example, mutations can
happen during cell division. Throughout life, an organism’s cells are constantly growing and dividing
via a highly regulated process called the cell cycle. This allows tissues to grow and stay healthy. Before
a cell divides, it must replicate its DNA (and therefore its genetic code), so that each of its two
daughter cells has identical DNA to the parent cell. DNA replication is a complex process and is
vulnerable to the introduction of errors in the DNA sequence. DNA can be damaged at other times too.
Cells are constantly exposed to factors that can damage DNA, either agents from the environment
outside the body (exogenous), such as radiation or chemicals in cigarette smoke, or agents generated
by processes that occur within the body (endogenous), such as free radicals or other by-products of
metabolism. A substance or agent that is capable of causing cancer is known as a carcinogen,
although not all carcinogens damage DNA directly. Ageing allows increasing opportunity for cells to
accumulate DNA damage. Ageing is also often accompanied by reduced capacity in many metabolic
and physiological functions, including protection against DNA damage.
Figure 3: Diet, nutrition and physical activity, other environmental exposures and host factors interact
to affect the cancer process (Diagram)
The process by which normal cells transform into invasive cancer cells and progress to clinically
significant disease typically spans many years. The cancer process is the result of a complex
interaction involving diet, nutrition and physical activity, and other lifestyle and environmental factors,
with host factors that are related both to inheritance and to prior experience, possibly through
epigenetic change. Such host factors influence susceptibility to cancer development, in particular
related to the passage of time. This allows both opportunities to accumulate genetic damage, as well
as impairment of function, for example, DNA repair processes with ageing. The interaction between
the host metabolic state and dietary, nutritional, physical activity and other environmental exposures
over the whole life course is critical to protection from or susceptibility to cancer development.
4. Cells can protect themselves against acquiring DNA damage and the hallmarks of cancer
Cells have evolved a range of mechanisms to prevent the accumulation of DNA damage, which
protects them against acquiring the hallmarks of cancer. These mechanisms include:
Eliminating or detoxifying external agents that can cause DNA damage – Cells can be exposed to a
multitude of substances and agents both natural and anthropogenic that have the potential to
damage DNA, disrupt normal cell function and contribute to carcinogenesis. Humans have evolved
various physiological mechanisms that protect against the adverse effects of some of these
carcinogens. For example, a family of enzymes termed ‘phase I and phase II metabolising enzymes’
are involved in a process that ultimately quenches, or neutralises, reactive agents that can damage
DNA so they can be excreted in bile or urine.
Repairing DNA damage so it is not transmitted to daughter cells Cells have a number of processes
that can detect and repair particular types of DNA damage. For example, normal progression through
the cell cycle is monitored at checkpoints that sense errors in DNA replication. Activation of these
checkpoints stops the cell cycle, allowing cells to repair any defects and prevent their transmission to
daughter cells.
Ensuring cells with damaged DNA do not survive – If DNA repair is unsuccessful and normal cell
function is compromised, damaged cells undergo a process called apoptosis, which means the cells
effectively self-destruct. This protects the tissues from accumulating cells with damaged DNA.
5. The protective mechanisms of cells sometimes fail, increasing the chances that cancer will
develop
The mechanisms that protect cells against accumulating DNA damage and the hallmarks of cancer
are not perfect and may be compromised by several factors that can increase the risk of cancer, such
as:
Inherited genetic defects – A small proportion of cancers (mean that a person will definitely go on to
develop cancer, but it does confer a higher risk of developing cancer compared with the general
population.
High levels of exposure to external carcinogens The physiological mechanisms that protect humans
against carcinogens may be overwhelmed by high levels of exposure and may not work as well to
protect against unaccustomed types of carcinogens that have appeared more recently, such as
industrial pollution.
Endogenous factors that compromise DNA integrity – Excessive production of reactive oxygen and
nitrogen species (ROS/ RNS) by neutrophils and macrophages, such as occurs with chronic
inflammation, can damage nuclear and mitochondrial DNA. Concomitant ROS/RNS damage to key
proteins such as DNA polymerases and multiple DNA repair enzymes regulating DNA integrity al
contribute to cancer susceptibility.
Reduced effectiveness of endogenous protective systems – Defects in DNA surveillance and repa
mechanisms as well as antioxidant defence systems can lead to genomic instability, meaning cells
accumulate deleterious DNA mutations more rapidly, giving them a predisposition to cancer and its
progression. This genetic instability provides a way for a previously healthy cell to accumulate
sufficient mutations to become malignant.
6. Inappropriate nutrition and levels of physical activity are conducive to cancer development-
Diet, nutrition and physical activity are essential aspects of human existence. Imbalanced and
inappropriate levels of these factors can disturb normal homeostasis and reduce resilience to
external challenges. This may manifest in many ways, for instance as susceptibility to
infections, to cardio metabolic disease or to cancer.
Diet, nutrition and physical activity may influence cancer risk in a range of different ways. Some foods
and drinks may be vectors for specific substances that act as carcinogens at particular sites. By
contrast, obesity and sedentary ways of life may not act through single discrete pathways – instead,
they may alter the systemic metabolic milieu of the body in ways that give rise to cellular
microenvironments that are conducive to cancer development at a number of sites.
There is accumulating evidence on how diet, nutrition and physical activity can have an impact on the
biological processes that underpin the development and progression of cancer – and influence
whether cells acquire the phenotypic changes in cellular structure and function that are
characterised as the hallmarks of cancer. For example:
Inappropriate nutrition at the whole body level is reflected in a disordered nutritional
microenvironment at the cellular and molecular levels. This can create an environment that is
conducive to the accumulation of DNA damage and therefore to cancer development.
Obesity is associated with inflammatory mediators, and metabolic and endocrine abnormalities, that
promote cell growth and exert anti-apoptotic effects, meaning cancer cells do not self-destruct even
following severe DNA damage.
Nutritional factors may influence mechanisms involved in DNA repair.
Dietary compounds may influence pathways by which carcinogens are metabolised.
Diet may influence epigenetic changes in cells.
Drinking alcohol can increase the production of metabolites that are genotoxic and carcinogenic.
Reduced functional capacity, which occurs with inappropriate nutrition (and with ageing), reduces
resilience to endogenous or external stresses.
Physical activity has been shown to promote healthy immune and hormonal systems. The growing
body of evidence on such biological processes adds weight to evidence on the effects of diet,
nutrition and physical activity on cancer risk measured at the level of the whole body indeed whole
populations in clinical of epidemiological studies
Body fatness and the hallmarks of cancer
This section fibres on links between body fatness and some of the hallmarks of cancer. While there
are links between the hallmarks and other exposures studied in the Continuous Update Project (CUP)
too, body fatness has been chosen as the example here because the evidence that greater body
fatness is a cause of many cancers is particularly strong, and has grown stronger over the last decade
(see also the Exposures: Body fatness and weight gain part of the Third Expert Report) What is more,
rates of overweight and obesity, in children as well as in adults, have been rising in most countries
[23].
The accumulating results of the CUP increasingly point to the importance of the systemic metabolic
milieu of the body as reflected in anthropometric measures such as body fatness as being a critical
determinant of cancer susceptibility (see Section 6.2: Assessing and interpreting evidence. Fine
tuning the approach in this Summary).
Maintaining a healthy weight throughout life is one of the most important ways to protect against
cancer. It also protects against a number of other common non-communicable diseases (NCDs), see
the Be healthy weight Recommendation in Section 5.1 and in the more detailed Recommendations
and public health and policy implications2 part of the Third Expert Report.
1. Sustained proliferative signalling
Many of the metabolic and endocrine abnormalities associated with obesity, such as elevated levels
of fasting insulin and oestradiol, as well as inflammatory mediators associated with obesity, exert
proliferative effects. Therefore, in the obese state, there is a general up-regulation of cell growth.
Unlike most healthy cells, cancer cells gradually evolve to become less dependent upon hormones
and growth factors for continued growth and replication. Cancer cells may acquire this ability by, for
example, producing growth-promoting signals themselves or by permanently activating the growth
and survival pathways that normally respond to growth factors, via mutations that lock in these
signals.
2. Resisting cell death
Normal cells ‘self-destruct’ under certain conditions, a process known as apoptosis. This happens,
for example, when a cell’s DNA is damaged beyond repair. In contrast, cancer cells can down regulate
apoptosis and survive even after severe DNA damage. Many of the metabolic and endocrine
abnormalities associated with obesity, such as elevated levels of fasting insulin and oestradiol, as
well as inflammatory mediators associated with obesity, exert anti-apoptotic effects. Therefore, in the
obese state, there is a suppression of apoptosis.
3. Activating invasion and metastasis
Cancer cells can infiltrate the local tumour microenvironment (invasion) and spread (metastasise) to
distant organs via the bloodstream or lymphatic system.
Certain tissues are particularly prone to acting as colonisation sites for metastatic tissue, such as the
liver, bones brain and lungs. This suggests that the specific microenvironment in these tissues is more
favourable for the support of tumours than that of other tissues, flody fatness is an importars
determinant of the tissue microenvironment. Obesity it also linked with metabolic reprogramming in
cancer cells so that they are more likely to metastasise.
4. Inducing angiogenesis
Angiogenesis is the term for the growth and establishment of a vascular network. As a tumour
develops, relying on the local vascular supply alone causes local hypoxia. This activates genes that
lead to the expression of growth factors, such as vascular endothelial growth factor (VEGF), thereby
stimulating the development of cancer-associated vascular networks, which are needed to support
tumour growth.
Adipose stromal cells may influence tumour vascularisation with associated increases in the
proliferative activity of tumour cells.
5. Genome instability and mutation
Genomic instability is an increased tendency of the genome to acquire mutations because of
dysfunction in the process of maintaining the genome. It can be thought of as an underlying enabling
characteristic, which expedites cells’ acquisition of the other hallmarks of cancer.
Human studies have linked the obese phenotype with genomic instability in colorectal and
endometrial cancer in women. Visceral obesity is also associated with genomic instability events,
both in vitro and in vivo in oesophageal adenocarcinoma.
6. Tumour-promoting inflammation
Tumour-promoting inflammation can also be thought of as an underlying enabling characteristic,
which can inadvertently contribute to cells’ acquisition of multiple other hallmark capabilities.
Chronic inflammation has long been recognised as a feature of cancer. Several inflammatory
conditions are established precursors for specific cancers, including gastritis for gastric cancer,
inflammatory bowel disease for colon cancer and pancreatitis for pancreatic cancer. Inflammation is
also well-established in the pathogenesis of ovarian cancer.
Chronic inflammation has been implicated in the link between nutrition and cancer in many
epidemiological and preclinical studies. In particular, obesity is now recognised as a chronic
inflammatory state that predisposes to cancer. Complex interactions between cellular, molecular and
metabolic factors underlie the nutrition-inflammation-cancer triad. For example, obesity is
associated with elevated secretion of several pro-inflammatory cytokines and with C-reactive protein
(an inflammation marker that is elevated with obesity, is related to cancer risk and reduces with
weight loss).
Dietary exposures and the hallmarks of cancer
There is evidence that other exposures, in addition to body fatness, increase or decrease the risk of
cancer at multiple cancer sites. This section provides examples of how dietary exposures might
influence cancer susceptibility.
1. Vegetables and fruit
Vegetables and fruit form a diverse and complex food group. Their consumption provides the host with
many micronutrients, as well as thousands of phytochemicals, which are not nutrients but may have
bioactivity in humans. Phytochemicals that have demonstrated anti-cancer effects in cell and rodent
studies include dietary fibre, carotenoids, dithiolthiones, isothiocyanates, flavonoids and phenols.
Vegetables and fruit are also a rich source of various nutrients that can impact cancer risk, such as
vitamins C and E. Selenium and folate. A substantial body of experimental data links many of these
compounds with anti-tumorigenic effects in various cells in both animal and in vitro models.
2. Red and processed meat
Examples of biological mechanisms thought to underlie the association of red and processed meat
with an increased risk of cancer include:
Cooking meats at high temperatures results in the formation of heterocyclic amines (HCAs) and
polycyclic aromatic hydrocarbons (PAHs), which have mutagenic potential through the formation of
DNA adducts and have been linked to cancer development in experimental studies.
Haem iron intake has been associated with an increased risk of colorectal tumours harbouring
transitions from guanosine to adenine in the KRAS and APC genes, which suggests that alkylating
DNA-damaging mechanisms are involved.
The high salt content of processed meat may result in damage to the stomach mucosal lining, leading
to inflammation, atrophy and Helicobacter pylori colonisation.
3. Alcoholic drinks
The diverse mechanisms by which alcohol consumption leads to cancer include:
Acetaldehyde, a toxic metabolite of ethanol oxidation, can be carcinogenic to some cell types (e.g.
colonocytes), due to conversion of ethanol to acetaldehyde by colonic bacteria.
Higher ethanol consumption can induce oxidative stress through increased production of reactive
oxygen species, which are genotoxic and carcinogenic.
Alcohol may also act as a solvent for cellular penetration of dietary or environmental (e.g. tobacco)
carcinogen, or interfere with retinoid and one-carbon metabolism and DNA repair mechanisms.
Alcohol has been linked to changes in hormone metabolism and, for example, is associated with
increased levels of oestradiol.
See also alcohol mechanisms in Appendix 2 of the Exposures. Alcoholic drinks part of the Thirs Expert
Report.
4. Physical activity and height and the hallmarks of cancer
There is strong evidence that physical activity and height both affect the risk of cancer at multiple
sites. The information below gives examples of the biological mechanisms that may be involved
Physical activity
Physical activity has a beneficial effect on cancer risk, likely through multiple mechanisms such as
reductions in circulating oestrogen levels, insulin resistance and inflammation all of which have been
linked to cancer development at various anatomical sites when increased. Physical activity also
reduces body fatness, in particular visceral fat, and therefore may have an additional indirect impact
Evidence on mechanisms includes the following:
Physical activity improves insulin sensitivity and reduces fasting insulin levels, which may decrease
the risk of breast cancer. It may also reduce circulating oestrogen levels.
Physical activity has been shown to have immunomodulatory effects, enhancing innate and acquired
immunity, and promoting tumour surveillance.
Studies have also shown that aerobic exercise can decrease oxidative stress and enhance DNA repair
mechanisms, decreasing carcinogenesis.
Height
Mechanisms hypothesised to underlie the association of greater adult attained height with increased
cancer risk include the following:
Taller people generally have higher circulating levels of IGF-I during adolescence and elevated
signalling through the insulin-IGF axis, which lead to activation of the phosphatidyl-3-kinase-mTOR
and MAPK pathways, causing cellular proliferation, suppressed apoptosis and angiogenesis.
Taller people may have more stem cells and thus there is greater opportunity for mutations leading to
cancer development.
Site-specific mechanisms may also be at play. For example, for colorectal cancer taller adults have
longer intestines with a greater number of cells at risk; therefore, there may be greater potential for
exposure to mutagenic or cancer-promoting agents.
Diagram
Several of the cancer hallmarks, and both enabling characteristics, can be affected by factors relating
to diet, nutrition and physical activity. Obesity illustrates the wide range of cellular and molecular
processes that may be affected to promote cancer development and progression. Abbreviations: ERK,
extracellular signal-regulated kinases; MAPK, mitogen-activated protein kinase; mTOR, mechanistic/
mammalian target of rapamycin; PI3K, phosphoinositide 3-kinase; STAT, signal transducer and
activator of transcription.
Potential impact of diet, nutrition, physical activity and height in increasing susceptibility to cancer
(table)
Abbreviations: AKT, also known as protein kinase B: DNA, deoxyribonucleic acid: ER+, oestrogen
receptor positive; ERK, extracellular signal-regulated kinases; IGF-I, insulin-like growth factor 1; KRAS,
please see mechanistic/mammalian target of rapamycin; NF-kB, nuclear factor kappa-light-chain
enhancer of glossary: MAPK, mitogenactivated protein kinase; mTOR, activated B cells; P53, tumour
protein p53; PI3K, phosphoinositide 3-kinase; STAT3, signal transducer and activator of transcription
3; WNT, Wingless-related integration site.
ecommendations for Cancer Prevention
The Cancer Prevention Recommendations, presented in this section are one of the most important
outputs of the Continuous Update Project (CUP). The Cancer Prevention Recommendations are
intended to reduce the incidence of cancer by helping people to maintain a healthy weight and adopt
healthy patterns of eating, drinking and physical activity throughout life, and by informing policy
action. The Recommendations take the form of a series of general statements to be used by
individuals, families, health professionals, communities and policymakers, as well as the media.
A whole-of-government, whole-of-society approach is necessary to create environments for people
and communities that are conducive to following the Cancer Prevention Recommendations. For more
information, see Section 5.3: Public health and policy implications in this Summary.
In addition to the Cancer Prevention Recommendations presented here, the importance of not
smoking, and of avoiding other exposure to tobacco, excess sun and long-term infections that can
cause cancer, is emphasised.
1. Making the Cancer Prevention Recommendations
The Panel uses its judgements on the findings of the CUP to make the Cancer Prevention
Recommendations.
The risk of other diseases, as well as cancer, is also modified by diet, nutrition and physical activity.
This includes diseases related to nutritional deficiencies, cardiovascular diseases (CVDs) and other
non-communicable diseases (NCDs). When making the Cancer Prevention Recommendations, other
recommendations on the prevention of these diseases made by authoritative international and
national organisations from around the world were therefore also taken into account.
2. An overall lifestyle
There are individual Recommendations on weight and physical activity and on particular aspects of
diet and nutrition. The Recommendations focus on foods and drinks, rather than on nutrients or other
bioactive constituents, for a variety of reasons.
It is important to emphasise that the Recommendations are intended to work together and be
adopted as a lifestyle package. Individual recommendations are likely to be less effective if followed in
isolation. Each has relevance for the others, and there are interactions between the exposures they
address. Together, the Recommendations promote an overall way of life – –
A healthy pattern of diet and physical activity
That is conducive to the prevention of cancer, other NCDs and obesity.
A growing body of evidence shows that the more people adhere to the 2007 Recommendations, the
greater the reductions in the risk of specific cancers, of cancer as a whole and of death from any
cause. Therefore, confidence in the protective effect from following all of the Recommendations is
greater than that for any individual Recommendation.
A diet based on the Recommendations is likely to be ‘nutrient dense’ – containing foods and
beverages with a relatively high concentration of vitamins and minerals and other dietary constituents
such as dietary fibre, without excessive salt, saturated or trans fats, added sugars or refined starches
thereby promoting good nutritional health and protecting against nutrient deficiency and NCDs.
3. Realistic and achievable goals
People interested in reducing their risk of cancer, health professionals who advise on preventing
cancer and people involved in the development of public health policy need specific, relevant advice
that they can act on. People need to know how much of what foods and drinks, what levels of body
fatness and how much physical activity are most likely to protect against cancer.
For these reasons, Goals are provided with each Recommendation. The Goals provide specific
advice, quantified whenever possible, on how to meet the Recommendations.
Goals are designed to result in real health gains while being achievable for most people. However,
even without fully achieving a stated Goal, a change toward the Goal is worthwhile – any change is
likely to provide at least some benefit. When quantifying the Goals, evidence from the CUP was taken
into account, as well as recommendations in other reports (on other NCDs, for example) on levels of
body fatness and physical activity, and of intake of foods and drinks. To minimise confusion, existing
quantified guidance has sometimes been selected from these other reports if consistent with the
evidence on cancer prevention.
4. Relevant worldwide
The Recommendations have been designed to be culturally relevant throughout the world. Most of the
available evidence comes from high-income countries, yet cancer is a problem worldwide. The
Recommendations are therefore designed to be achievable in and appropriate to the very different
circumstances and cultures that exist throughout the world.
Some evidence from the CUP is strong enough to support recommendations but is not suitable for
inclusion in a set of global recommendations for a variety of reasons.
5. Introducing the Recommendations
There are 10 Cancer Prevention Recommendations. Each Recommendation is intended to be one in a
comprehensive package of behaviours that, when taken together, promote a healthy pattern of diet
and physical activity conducive to the prevention of cancer, other NCDs and obesity. Evidence that
greater body fatness is a cause of many cancers is particularly strong; hence the following
Recommendation is presented first:
Be a healthy weight
The following two Recommendations promote positive changes that can be made to reduce both the
risk of cancer and the risk of weight gain, overweight and obesity (which themselves are associated
with an increased risk of cancer):
Be physically active
Eat a diet rich in whole grains, vegetables, fruit and beans
The next four Recommendations focus on what to limit to reduce the risk of cancer, or of weight gain,
overweight and obesity, and are listed in order by foods and drinks:
Limit consumption of ‘fast foods’ and other processed foods high in fat, starches or sugars
Limit consumption of red and processed meat
Limit consumption of sugar sweetened drinks
Limit alcohol consumption
The next Recommendation relates to supplements:
Do not use supplements for cancer prevention
Two special Recommendations aimed at specific groups of people follow:
For mothers: breastfeed your baby, if you can
After a cancer diagnosis: follow our Recommendations, if you can
RECOMMENDATION
Be a healthy weight
Keep your weight within the healthy range and avoid weight gain in adult life
Ensure that body weight during childhood and adolescence projects towards the lower end of the
healthy adult BMI range
Keep your weight as low as you can within the healthy range throughout life
Avoid weight gain (measured as body weight or waist circumference) throughout adulthood
Overweight and obesity, generally assessed by various anthropometric measures including body
mass index (BMI) and waist circumference, are now more prevalent than ever. In 2016, an estimated
1.97 billion adults and over 338 million children and adolescents were categorised as overweight or
obese globally. The increase in the proportion of adults categorised as obese has been observed both
in low- and middle-income countries and in high-income countries.
Goals
Ensure that body weight during childhood and adolescence projects towards the lower end of the
healthy adult BMI range.
Keep your weight as low as you can within the healthy range throughout life. These two related Goals
emphasise the importance of preventing excess weight gain, overweight and obesity, beginning in
childhood.
Avoid weight gain (measured as body weight or waist circumference) throughout adulthood.
As there may be adverse effects specifically from gaining weight during adulthood, it is best to
maintain weight within the healthy range throughout adult life.
This overall Recommendation is best achieved by maintaining energy balance throughout life by
following four of the other Recommendations:
Being physically active
Eating a diet rich in whole grains, vegetables, fruit and beans
Limiting consumption of ‘fast foods’ and other processed foods high in fat, starches or sugars
limiting consumption of sugar sweetened drinks.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP:
Greater body fatness is a cause of many cancers. This evidence has become stronger over the last
decade.
For some cancers the increase in risk is seen with increasing body fatness even within the so-called
‘healthy range. Nevertheless, most benefit is to be gained by avoiding overweight and obesity.
The International Agency for Research on Cancer (IARC) reviewed evidence for three additional
cancers and concluded that greater body fatness is a cause of thyroid cancer, multiple myeloma and
meningioma.
Overweight and obesity in childhood and early life are liable to be carried through to adulthood.
Implications for other diseases
It is well established that greater body fatness has a causal role in the development of several other
disorders and diseases, such as type 2 diabetes, dyslipidaemia, hypertension, stroke and coronary
heart disease, as well as digestive and musculoskeletal disorders. People with obesity often develop
several of these disorders or diseases, leading to multiple comorbidities.
Public health and policy implications
A comprehensive package of policies is needed to enable people to achieve and maintain a healthy
weight, including policies that influence the food environment, food system, built environment and
behaviour change communication across the life course. These policies can also help contribute to a
sustainable ecological environment. Policymakers are encouraged to frame specific goals and
actions according to their national context.
RECOMMENDATION
Be physically active
Be physically active as part of everyday life -walk more and sit less
Be at least moderately physically active, and follow or exceed national guidelines
Limit sedentary habits
In most parts of the world, levels of physical activity are insufficient for optimal health. Sedentary
ways of life have become common in high-income countries since the second half of the 20th century
and have subsequently also become widespread in most populations around the world.
Goals
Be at least moderately physically active, and follow or exceed national guidelines.
Establish a daily habit of being physically active throughout life, including when older. People whose
work is sedentary need to take special care to build some physical activity into everyday life
WHO advises adults to be active daily, taking part throughout each week in at least 150 minutes of
moderate-intensity, aerobic physical activity or at least 75 minutes of vigorous, aerobic physical
activity (or a combination). This represents a minimum amount of physical activity for cardio
metabolic health.
For cancer prevention, it is likely that the greater the amount of physical activity, the greater the
benefit. To have a significant impact on weight control, higher levels of activity are required (45-60
minutes of moderate-intensity physical activity per day).
Children and young people aged 5 to 17 are advised to accumulate at least 60 minutes of moderate to
vigorous-intensity physical activity daily. Being physically active for longer than 60 minutes provides
additional health benefits.
Activities that are moderate in intensity include walking, cycling, household chores, gardening and
certain occupations, as well as recreational activities such as swimming and dancing. Vigorous
activities include running, fast swimming, fast cycling, aerobics and some team sports.
Limit sedentary habits
Both adults and children are advised to minimise the amount of time spent being sedentary for
extended periods.
For adults, many occupations involve prolonged periods of sitting.
For both adults and children, watching screens (including when working) on devices such as
televisions, computers, smartphones and video games is a form of sedentary behaviour. In some
countries, children commonly spend more than three hours a day on such devices, during which they
are also often exposed to heavy marketing of highly processed foods and drinks high in fat, refined
starches or sugars. Screen time may also be associated with consumption of energy dense snacks
and drinks.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP:
Physical activity helps protect against several cancers.
Physical activity, including walking, helps protect against weight gain, overweight and obesity.
Greater screen time is a cause of weight gain, overweight and obesity.
Greater body fatness is a cause of many cancers.
A lack of physical activity and sedentary lifestyles are both globally widespread
In most parts of the world, levels of physical activity are insufficient for optimal health
Sedentary ways of life have become common in high-income countries since the second half of the
20th century and have subsequently also become widespread in most populations around the world.
Implications for other diseases
Regular physical activity of at least moderate intensity decreases the risk of all-cause mortality.
Coronary heart disease, high blood pressure, stroke, type 2 diabetes, metabolic syndrome and
depression.
Regular weight-bearing and muscle strengthening exercise has documented health benefits,
including promoting bone health and reducing blood pressure.
Greater body fatness is a common risk factor for many other diseases and disorders, including
cardiovascular disease (CVD) and type 2 diabetes.
Public health and policy implications
A comprehensive package of policies is needed to promote and support physical activity, including
policies that influence the food environment, food system, built environment and behaviour change
communication across the life course. These policies can also help contribute to a sustainable
ecological environment. Policymakers are encouraged to frame specific goals and actions according
to their national context.
RECOMMENDATION
Eat a diet rich in wholegrains, vegetables, fruit and beans
Make wholegrains, vegetables, fruit, and pulses (legumes) such as beans and lentils a major part of
your usual daily diet
Consume a diet that provides at least 30 grams per day of fibre’ from food sources
Include in most meals foods containing wholegrains, non-starchy vegetables, fruit and pulses
(legumes) such as beans and lentils
Eat a diet high in all types of plant foods Including at least five portions or servings (at least 400 grams
or 15 ounces in total) of a variety of non-starchy vegetables and fruit every day
If you eat starchy roots and tubers as staple foods, eat non-starchy vegetables, fruit and pulses
(legumes) regularly too if possible
Relatively unprocessed foods of plant origin are rich in nutrients and dietary fibre. Higher
consumption of these foods instead of processed foods high in fat, refined starches and sugars1
would provide a diet that is higher in essential nutrients and more effective for regulating energy intake
relative to energy expenditure. This could protect against weight gain, overweight and obesity and
therefore protect against obesity related cancers. Whole grains, non-starchy vegetables, fruit and
beans are a consistent feature of diets associated with lower risk of cancer and other non
communicable diseases (NCDs), as well as obesity.
Goals
Consume a diet that provides at least 30 grams per day of fibre from food sources.
Include in most meals foods containing whole grains, non-starchy vegetables, fruit and pulses
(legumes) such as beans and lentils.
Eat a diet high in all types of plant foods including at least five portions or servings (at least 400 grams
or 15 ounces in total) of a variety of non-starchy vegetables and fruit every day.
The goal for fibre intake can be met by eating a range of foods of plant origin, including whole grains
and non-starchy vegetables and fruit of different colours (for example, red, green, yellow, white,
purple and orange).
Examples of whole grains include brown rice, wheat, oats, barley and rye.
Examples of non-starchy vegetables include green leafy vegetables, broccoli, okra, aubergine
(eggplant) and bok choy, but not, for instance, potatoes, yams or cassava.
For the purposes of this Recommendation, non-starchy roots and tubers such as carrots, artichokes,
celeriac (celery root), swede (rutabaga) and turnips are considered to be non starchy vegetables.
One portion of non-starchy vegetables or fruit is approximately 80 grams or 3 ounces. If consuming
the recommended amount of vegetables and fruit, consumption would be at least 400 grams or 15
ounces per day.
If you eat starchy roots and tubers as staple foods, eat non-starchy vegetables, fruit and pulses
(legumes) regularly too if possible.
In many parts of the world, traditional food systems are based on roots or tubers such as cassava,
sweet potatoes, yams and taro. Where appropriate, it is advisable to protect traditional food systems
in addition to their cultural value, and their suitability to local climate and terrain, they are often
nutritionally superior to the diets that tend to displace them. However, monotonous traditional diets,
especially those that contain only small amounts of non-starchy vegetables, fruit and pulses
(legumes), are likely to be low in essential micronutrients and thereby increase susceptibility to some
cancers.
Whole grains, non-starchy vegetables, fruit and pulses (legumes) all contain substantial amounts of
fibre and a variety of micronutrients, and are low or relatively low in energy density. For cancer
prevention, it is best if these, and not foods of animal origin, are the basis for a usual daily diet.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP: Consuming whole grains helps protect against colorectal
cancer.
➤ Consuming dietary fibre helps protect against colorectal cancer and weight gain, overweight and
obesity.
➤ Greater body fatness is a cause of many cancers.
➤ Although the evidence for links between individual cancers and consumption of non-starchy
vegetables or fruit is limited, the pattern of association and the direction of effect are both consistent.
Overall the evidence is more persuasive of a protective effect and that greater consumption of non
starchy vegetables and or fruit helps protects against a number of aero digestive cancers and some
other cancers.
There is some evidence from the CUP to suggest:
Consuming fruit and vegetables might decrease the likelihood of many cancers.
Consuming fruit and vegetables might decrease the likelihood of weight gain, overweight and obesity.
People who eat no or low levels of vegetables and fruit, who increase their consumption, may benefit
most from following this Recommendation
Whole grains, non-starchy vegetables, fruit and beans are a consistent feature of diets associated
with lower risk of cancer and other NCDs, as well as obesity.
Relatively unprocessed foods of plant origin are rich in nutrients and dietary fibre Higher consumption
of these foods instead of processed foods high in fat, refined starches and sugars would mean the diet
is higher in essential nutrients and more effective for regulating energy intake relative to energy
expenditure.
Implications for other diseases
The Goals and Recommendation on whole grains, vegetables, fruit and beans are based on evidence
on cancer, but are supported by evidence on cardiovascular disease and type 2 diabetes.
Greater body fatness is a common risk factor for many other diseases and disorders, including
cardiovascular diseases (CVDs) and type 2 diabetes.
Public health and policy implications
A comprehensive package of policies is needed to promote and support physical activity, including
policies that influence the food environment, food system and behaviour change communication
across the life course. These policies can also help, contribute to a sustainable ecological
environment. Policymakers are encouraged to frame specific goals and actions according to their
national context.
Overweight and obesity are at the highest levels ever seen globally. Processed foods high in fat,
starches or sugars embody a cluster of characteristics that encourage excess energy consumption,
for example, by being highly palatable, high in energy, affordable, easy to access and convenient to
store.
Goal
Limit consumption of processed foods high in fat, starches or sugars including ‘fast foods’; many pre
prepared dishes, snacks, bakery foods and desserts; and confectionery (candy)
This Recommendation does not imply that all foods high in fat need to be avoided. Some, such as
certain oils of plant origin, nuts and seeds, are important sources of nutrients. Their consumption has
not been linked with weight gain and by their nature they tend to be consumed in smaller portions.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP: Consuming ‘fast foods’ (readily available convenience foods
that tend to be energy dense and are often consumed frequently and in large portions) is a cause of
weight gain, overweight and obesity.
Consuming a Western type’ diet (characterised by a high amount of free sugars, meat and fat) is a
cause of weight gain, overweight and obesity.
Glycaemic load (the increase in blood glucose (and insulin) after consumption of food) is a cause of
endometrial cancer.
Greater body fatness is a cause of many cancers.
The increasing availability, affordability and acceptability of ‘fast foods and other processed foods
high in fat, starches or sugars (which are highly palatable, high in energy and convenient to store) is
contributing to rising rates of overweight and obesity worldwide.
Implications for other diseases
Limited intake of processed foods high in fat, starches or sugars is recommended by many other
organisations to reduce the risk of several non-communicable diseases (NCDs).
Limiting intake of ‘fast foods’ and other processed foods high in fat, starches or sugars reduces the
risk of weight gain, overweight and obesity. Greater body fatness is a common risk factor for many
other diseases and disorders, including cardiovascular diseases (CVDs) and type 2 diabetes
Public health and policy implications
A comprehensive package of policies is needed to limit the availability, affordability and acceptability
of ‘fast foods’ and other processed foods, including policies that restrict marketing of such foods,
especially to children. Policies are needed that influence the food environment, food system and
behaviour change communication across the life course. These policies can also help contribute to a
sustainable ecological environment. Policymakers are encouraged to frame specific goals and
actions according to their national context.
RECOMMENDATION
Limit consumption of red and processed meat
Eat no more than moderate amounts of red meat’, such as beef, pork and lamb. Eat little, if any,
processed meat
If you eat red meat, limit consumption to no more than about three portions per week. Three portions
is equivalent to about 350 to 500 grams (about 12 to 18 ounces) cooked weight of red meat. Consume
very little, if any, processed meat
An integrated approach to the evidence shows that diets that reduce the risk of cancer and other non
communicable diseases (NCDs) contain no more than modest amounts of red meat and little or no
processed meat.
Goal
➤ If you eat red meat, limit consumption to no more than about three portions per week. Three
portions is equivalent to about 350 to 500 grams (about 12 to 18 ounces) cooked weight of red meat.
Consume very little, if any, processed meat.
The Recommendation is not to completely avoid eating meat; meat can be a valuable source of
nutrients, in particular protein, iron, zinc and vitamin B12. However, it is not necessary to consume
red meat in order to maintain adequate nutritional status. People who choose to eat meat-free diets
can obtain adequate amounts of these nutrients through careful food selection. Protein can be
obtained from a mixture of whole grains (cereals) and pulses (legumes), such as beans and lentils.
Iron is present in many plant foods, though it is less bioavailable than that in meat.
Poultry and fish are valuable substitutes for red meat. Eggs and dairy are also valuable sources of
protein and micronutrients for people who do eat other foods of animal origin.
High consumers of red meat and processed meat who reduce their intakes are expected to gain the
greatest benefit from following this Recommendation.
Opportunities to use refrigeration to preserve fresh meat remain limited in some countries, where
processed meat might be an important source of protein and iron.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP:
Consuming red meat and consuming processed meat are causes of colorectal cancer.
Red meat is a good source of protein, iron and other micronutrients (although consumption of red
meat is not necessary to maintain adequate nutritional status).
The amount of red meat specified in the Recommendation was chosen to provide a balance between
the advantages of eating red meat (as a source of essential macro and micronutrients) and the
disadvantages (an increased risk of colorectal cancer and other NCDs).
Processed meat is generally energy dense, can contain high levels of salt, and some of the methods
used to create it generate carcinogens.
The data on processed meat show that there is no level of intake that can confidently be associated
with a lack of risk of colorectal cancer.
Implications for other diseases
Greater consumption of red and processed meat is associated with increased risk of death from
cardiovascular disease (CVD) and risk of stroke and type 2 diabetes.
Eating patterns that include a low intake of meat, processed meat and processed poultry are
associated with reduced risk of CVD in adults and possibly of type 2 diabetes.
Meat is an important source of iron but restricting the amount of red meat consumed per person Per
week to a maximum of 350 to 500 grams would have little effect on the proportion of adults with iron
intakes below recommended levels in people eating a mixed diet. If unbalanced, vegetarian diets may
increase the risk of iron deficiency.
Public health and policy implications
A comprehensive package of policies is needed to support people to consume diversified diets
including limited red meat and little, if any, processed meat, including policies that influence the food
environment, food system and behaviour change communication across the life course. Globally,
food systems that are directed towards foods of plant rather than animal origin are more likely to
contribute to a sustainable ecological environment. Policymakers are encouraged to frame specific
goals and actions according to their national context.
RECOMMENDATION
Limit consumption of sugar sweetened drinks
Drink mostly water and unsweetened drinks
Do not consume sugar sweetened drinks¹
Consumption of sugar sweetened drinks is increasing in many countries worldwide and is
contributing to the global increase in obesity, which increases the risk of many cancers.
Goal
Do not consume sugar sweetened drinks.
To maintain adequate hydration, it is best to drink water or unsweetened drinks, such as tea (Camellia
sinensis) or coffee without added sugar.
Coffee and tea both contain caffeine. For healthy adults, the maximum safe daily intake of caffeine
recommended by the European Food Safety Authority is 400 milligrams per day (approximately four
cups of brewed coffee). The limit is lower in pregnancy.
Do not consume fruit juices in large quantities, as even with no added sugar they are likely to promote
weight gain in a similar way to sugar sweetened drinks. Most national guidelines now recommend
limiting intake of fruit juice.
There is no strong evidence in humans to suggest that artificially sweetened drinks with minimal
energy content, such as diet sodas, are a cause of cancer.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP:
Consuming sugar sweetened drinks (which provide energy but may not reduce appetite) is a cause of
weight gain, overweight and obesity in both children and adults, especially when consumed
frequently or in large portions. This effect is compounded at low levels of physical activity.
Sugar sweetened drinks do so by promoting excess energy intake relative to energy expenditure.
Greater body fatness is a cause of many cancers.
Consumption of sugar sweetened drinks has rapidly increased in many parts of the world, especially
in low- and middle-income countries, contributing to rising rates of overweight and obesity. Although
sales of sugar sweetened drinks have decreased in many high-income countries over the same
period, total consumption has remained high.
Implications for other diseases
Greater body fatness is a common risk factor for many other diseases and disorders, including
cardiovascular disease (CVD) and type 2 diabetes.
Some evidence suggests regular consumption of sugar sweetened drinks increases the risk of type 2
diabetes independently of effects on adiposity.
Consumption of sugar sweetened drinks is a cause of dental caries and impaired oral health,
particularly in children.
Public health and policy implications
A comprehensive package of policies is needed to limit the availability, affordability and acceptability
of sugar sweetened drinks, including marketing restrictions and taxes on sugar sweetened drinks, and
securing access to clean water (this is of particular relevance to school settings). Policies are needed
that influence the food environment, food system and behaviour change communication across the
life course. These policies can also help contribute to al sustainable ecological environment.
Policymakers are encouraged to frame specific goals and actions according to their national context.
RECOMMENDATION
Limit alcohol consumption
For cancer prevention, it’s best not to drink alcohol
For cancer prevention, it’s best not to drink alcohol
Consuming alcoholic drinks is a cause of many cancers. There is no threshold for the level of
consumption below which there is no increase in the risk of at least some cancers.
Goal
For cancer prevention, it’s best not to drink alcohol. If you do consume alcoholic drinks, do not
exceed your national guidelines. Children should not consume alcoholic drinks. Do not consume
alcoholic drinks if you are pregnant.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP:
Drinking alcohol is a cause of many cancers.
Drinking alcohol helps protect against kidney cancer (at least up to 30 grams or two drinks per day),
but this is far outweighed by the increased risk for other cancers.
Evidence from the CUP also shows:
Even small amounts of alcoholic drinks can increase the risk of some cancers-there is no level of
consumption below which there is no increase in the risk of at least some cancers.
Alcoholic drinks of all types have a similar impact on cancer risk. This Recommendation therefore
covers all types of alcoholic drinks.
Implications for other diseases
Studies suggest some people who consume small amounts of alcohol may have lower risks of
coronary heart disease (CHD) and early death than non-drinkers, but only at low levels of
consumption (about one unit a day).
Heavy alcohol use is overwhelmingly detrimentally related to many cardiovascular diseases (CVDs),
including hypertensive disease, haemorrhagic stroke and atrial fibrillation. Alcohol consumption is
associated with various kinds of liver disease – with fatty liver, alcoholic hepatitis and cirrhosis being
the most common – and with an increased risk of pancreatitis.
Despite the uncertainties about the effects of moderate alcohol consumption on non-cancer
outcomes, drinking alcohol is not recommended for any health benefit.
Public health and policy implications
A comprehensive package of policies is needed to reduce alcohol consumption at a population level,
including policies that influence the availability, affordability and marketing of alcoholic drinks.
Policymakers are encouraged to frame specific goals and actions according to their national context.
RECOMMENDATION
Do not use supplements for cancer prevention
Aim to meet nutritional needs through diet alone
High-dose dietary supplements are not recommended for cancer prevention – aim to meet nutritional
needs through diet alone
For most people consumption of the right food and drink is more likely to protect against cancer than
consumption of dietary supplements.
Goal
High-dose dietary supplements are not recommended for cancer prevention nutritional needs
through diet alone. Aim to meet
This Recommendation applies to all doses and formulations of supplements, unless supplements
have been advised by qualified health professional, who can assess individual requirements as well
as potential risks and benefits.
In some situations for example, in preparation for pregnancy or in dietary inadequacy supplements
may be advisable to prevent nutrient or calorie deficiencies. In general though, for otherwise healthy
people with secure access to a regular supply of a variety of foods and drinks, nutrient-dense diets
can provide adequate intake of nutrients.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP:
Taking high-dose beta-carotene supplements is a cause of lung cancer in current and former
smokers.
Trials of other high-dose supplements have not consistently demonstrated the protective effects of
micronutrients on cancer risk suggested by observational studies. Although taking calcium
supplements helps protect against colorectal cancer, some trials for other cancer sites have shown
potential for unexpected adverse effects.
Disparity between the beneficial effects of micronutrients from foods observed in long-term dietary
data and the lack of beneficial effects observed in short term supplements trial data can lead to
uncertainty as to the effect of dietary supplements on cancer risk.
For most people, it is possible to obtain adequate nutrition from a healthy diet that includes the right
foods and drinks.
Implications for other diseases
Supplementation may be needed to achieve adequate intake of nutrients in populations or people
with nutrient insufficiency. For example, people with dietary anaemia may need iron or folic acid
supplementation. To promote bone health, adequate calcium intakes and adequate supply of vitamin
D are required; supplementation is sometimes necessary.
Public health and policy implications
In many parts of the world, nutritional inadequacy is endemic and may increase the risk of non
communicable diseases (NCDs). In crisis situations it is necessary to supply supplements of
nutrients to such populations or to fortify food to ensure at least minimum adequacy of nutritional
status.
The best approach is to protect or improve local food systems so that they are nutritionally adequate
and promote healthy diets. This also applies in high-income countries, where impoverished
communities and families, vulnerable people including those living alone, the elderly, and the
chronically ill or infirm, may also be consuming nutritionally inadequate diets. Again, in such cases of
immediate need, supplementation is necessary.
Policymakers are advised to maximise the proportion of the population achieving nutritional
adequacy without dietary supplements by implementing policies that create a healthy food
environment and food system. Policymakers are encouraged to frame specific goals and actions
according to their national context.
RECOMMENDATION
For mothers: breastfeed your baby, if you can
Breastfeeding is good for both mother and baby
This recommendation aligns with the advice of the World Health Organization, which recommends
infants are exclusively breastfed for 6 months, and then up to 2 years of age or beyond alongside
appropriate complementary foods
Data from the World Health Organization (WHO) show that the percentage of infants who are
exclusively breastfed for the first 6 months of life is highest in low-income countries (47 per cent) and
lowest in upper middle-income countries (29 per cent). The global average prevalence is 36 per cent.
Goal
This recommendation aliens with the advice of the World Health Organization, which recommends
infants are exclusively breastfed for 6 months, and then up to 2 years of age or beyond alongside
appropriate complementary foods.
The benefits for both mother and baby are greater the longer the cumulative duration of
Breastfeeding. Breastfeeding is recommended with caution or not advised in some situations, for
example, for mothers with HIV/AIDS; see WHO guidance for further information.
Justification
This recommendation was made for several reasons:
There is strong evidence from the CUP:
Breastfeeding helps protect the mother against breast cancer.
Having been breastfed helps protect children against excess weight gain, overweight and obesity.
Greater body fatness is a cause of many cancers.
Excess body fatness during childhood tends to track into adult life.
Excess body fatness during childhood is associated with an earlier menarche in girls, which in turn
increases the risk of several cancers.
Breastfeeding protects the development of the immature immune system and protects against
infections in infancy and other childhood diseases.
Breastfeeding is vital where water supplies are not safe.
Breastfeeding is important for the development of the bond between mother and child.
In most countries, only a minority of mothers exclusively breastfeed their babies until 4 months, and
an even smaller number until 6 months. Increasing the rate of exclusive breastfeeding is one of WHO’s
Global Nutrition Targets 2025.
Implications for other diseases
The incidence of infections, as well as mortality rates, during infancy are lower in Children who are
breastfed. Benefits continue into childhood and adulthood, with lower risks of other diseases, such as
asthma. There is some evidence to suggest risk of type 2 diabetes is reduced in adulthood.
Mothers who breastfeed have a lower risk of type 2 diabetes.
Greater body fatness is a common risk factor for many other diseases and disorders, including
cardiovascular diseases (CVDs) and type 2 diabetes.
Public health and policy implications
A comprehensive package of policies is needed to promote, protect and support breastfeeding,
including making all hospitals supportive of breastfeeding, providing counselling in healthcare
settings, implementing maternity protection in the workplace, and regulating marketing of breast milk
substitutes. Policymakers are encouraged to frame specific goals and actions according to their
national context.
RECOMMENDATION
After a cancer diagnosis: follow our Recommendations, if you can
Check with your health professional what is right for you
All cancer survivors should receive nutritional care and guidance on physical activity from trained
professionals
Unless otherwise advised, and if you can, all cancer survivors are advised to follow the Cancer
Prevention Recommendations as far as possible after the acute stage of treatment
The circumstances of cancer survivors vary greatly. There is increased recognition of the potential
importance of diet, nutrition, physical activity and body fatness in cancer survival. People who have
been diagnosed with cancer should consult an appropriately trained health professional as soon as
possible, who can take each person’s circumstances into account.
Goals
All cancer survivors should receive nutritional care and guidance on physical activity from trained
professionals.
There is increased recognition of the potential importance of diet, nutrition, physical activity and body
fatness in cancer survival. Circumstances of cancer survivors vary greatly and people who have been
diagnosed with cancer should be given the opportunity, as soon as possible, to consult an
appropriately trained health professional who can take each person’s Orcumstances into account.
People who are undergoing treatment for cancer are likely to have special nutritional requirements, as
are people after treatment whose ability to consume of metabolise food has been altered by
treatment, and people in the later stages of cancer whose immediate need is to arrest or slow down
weight loss. The advice of an appropriately trained health professional is essential in all of these
situations.
The evidence does not support the use of supplements as a means of improving survival. However,
supplements may be specifically advised by an appropriately trained professional for other reasons.
GOAL
Unless otherwise advised, and if you can, all cancer survivors are advised to follow the Cancer
Prevention Recommendations as far as possible after the acute stage of treatment.
There is growing evidence that physical activity and other measures that control weight (both features
of the Cancer Prevention Recommendations) may help to improve survival and health-related quality
of life after a breast cancer diagnosis.
Justification
This recommendation was made for several reasons:
For breast cancer survivors, there is persuasive evidence that nutritional factors (in particular body
fatness) and physical activity reliably predict important outcomes from breast cancer. However, the
evidence that changing these factors would alter the clinical course of breast cancer is limited,
particularly by the quality of published studies.
Although research on the effects of diet, nutrition and physical activity and the risk of cancer is
growing, only evidence on the effects of these lifestyle factors on survival and future risk of breast
cancer has been reviewed. This is currently the best evidence available.
The current understanding of the biology of cancer and its interactions with diet, nutrition and
physical activity supports this Recommendation.
More people are surviving cancer than ever before, at least partly because of earlier detection and
increasing success of treatment for many cancers. As a result, cancer survivors are living long enough
to develop new primary cancers or other non-communicable diseases (NCDs). Following the Cancer
Prevention Recommendations may improve survival and reduce the risk both of cancer and of other
NCDs.
Implications for other diseases
Evidence shows that following a dietary pattern close to the Cancer Prevention Recommendations is
likely to help prevent other NCDs as well as to help management and control of co-existing NCDs,
which can complicate treatment and reduce survival.
Public health and policy implications
A comprehensive whole-of-government, whole of-society approach is necessary to create
environments for cancer survivors that are conducive to following the Cancer Prevention
Recommendations, and future, more specific evidence-based recommendations.
Why is it important to eat well when you have cancer?
Eating well when you have cancer can help you feel better. It can make you feel strong and help you to
maintain a healthy weight. It can also help you tolerate the side-effects of treatment, reduce the risk
of infection, and help your recovery.
➤ What is a balanced diet?
Having a balanced diet means that your body has the nutrition it needs to grow and work well. It may
also help to prevent illness.
To have a balanced diet you need to eat a variety of foods that provide the nutrients your body needs in
the right amounts. These include protein, carbohydrates, fats, vitamins and minerals. They are used
by your body to give you energy, repair and build essential tissues, and help with lots of body
functions.
If you have cancer, eating a balanced diet is even more important during treatment. It can
Help you to:
Feel better
Keep up your energy and strength
Keep a healthy weight
Tolerate the dose of drugs given
Cope better with side-effects of treatment
Reduce your risk of infection
Heal and recover faster
➤ The food pyramid
The food pyramid on pages 8-9 can help you to see how to balance your own diet, by getting the right
amount of different types of foods.
Cancer and cancer treatment can affect your body in different ways. You may need to eat different
types of foods or different quantities. You might need special advice from a dietician to keep a good
balance in your diet. Ask to be referred to the dietician if you have any worries about your diet.
Diagram
What is a serving?
Serving sizes vary depending on the type of food. 1 serving is:
Meat: A piece about the size of your palm
Fruit: 1 banana, 2 plums or 6 strawberries
Vegetables: Around half a 200ml disposable plastic cup
Potatoes: 2 medium or 4 small
Pasta or rice: A 200ml disposable plastic cup full
Bread: 2 thin slices
Cheese: A piece the size of 2 thumbs
Milk: One glass
Oil: 1 teaspoon per person when cooking
Spreads: 1 portion pack size
Eating and cooking tips
Prepare and cook your meals using fresh ingredients. Avoid ready meals and takeaways in general
Always read the nutrition label: check for high levels of fat, sugar and salt.
Eat more fish, especially oily fish such as mackerel, sardines and salmon, at least once a week.
Drink about 8-10 cups or glasses of fluid every day. Water is best.
Eat slowly and chew your food properly.
Eat breakfast-you’re more likely to be a healthy weight if you do.
Limit or avoid alcohol and don’t drink on an empty stomach.
If you eat a healthy balanced diet, there is no need to take food supplements, unless advised by your
doctor.
➤ What is a healthy weight?
A healthy weight is when your weight is right for your height, your body mass index (BMI) is normal and
you are neither overweight nor underweight. The best way to be a healthy body weight is to balance
the food and drink you eat with physical activity.
How do I know if I’m a healthy weight?
If you’re not sure about your weight, ask your dietician for advice. One way to check it is by finding your
body mass index. BMI is a number that tells if your weight is right for your height.
BMI is graded so it can tell if you are underweight, a healthy weight, overweight or obese (fat)
Your dietician can measure your BMi for you. Sometimes there are scales in shopping centres or
pharmacies that will measure it for you. BMI is a guide only. If you are worried about your score, do talk
to your dietician. Most people are advised to keep their current body weight during cancer treatment.
If you are losing or gaining weight, discuss it with your nurse, doctor or dietician
Measuring BMI yourself
You can also calculate your BMI yourself. But first you will need to know your weight in kilograms (kg)
and your height in metres (m). Divide your weight by your height and then divide the result again by
your height. There are also websites that can help you to calculate it.
Waistline measurement
Measuring your waistline is a way of checking if you are at risk of cancer, especially bowel cancer.
Extra weight around your middle can also lead to health problems such as diabetes and heart
disease.
To measure your waistline:
Find the top of your hipbone.
At this point, measure around your waist. Make sure the tape measure is snug but not marking your
skin.
Take the measurement at the end of a normal breath.
Your risk of cancer is higher if your waistline is more than 94 cm or 37 inches for men and more than
80 cm or 32 inches for women. Talk to your dietician if you are worried about your waistline.
Nutrition and treatment
How might cancer treatment affect how I eat?
Some cancer treatments can affect your appetite or how you eat. For example, how you chew,
swallow and absorb food. Before any treatment, your doctor and nurse will explain any likely side
effects.
Sometimes it can be hard to know what kind of eating problems to expect. It can depend on several
things, for example:
Location of your cancer and if it has spread
Type of treatment given
Area being treated
Number of treatments.
Dose of treatment given
Length of treatment
Symptoms caused by the cancer
Side-effects of treatment
Your own general health
Referral to a dietician
Cancer or the side-effects of treatment can reduce your appetite or cause weight loss. This can make
you weak and tired, more likely to get infections or less able to tolerate treatment. Ask to be referred to
a dietician if you are underweight or losing weight or have any concerns during your treatment.
Surgery
It’s common to have some eating problems after surgery. Usually most people can start eating again a
day or two after surgery. If you have surgery to your digestive system, the eating problems may take
longer to clear up. This includes surgery to your mouth, tongue, throat, gullet (oesophagus), stomach,
small intestine, bowel, rectum, pancreas, liver, and gallbladder.
Some common eating problems after surgery include:
Feeling full
Swallowing problems
Loss of appetite
Nausea
Vomiting
Cramping
Diarrhoea
Constipation
Weight gain or loss
Because surgery may slow your digestion or affect your mouth, throat and stomach, you will need
good nutrition. Good nutrition will help your wound to heal well and speed up your recovery. In some
cases, you might need tube feeding after your surgery.
Eating tips before surgery
Your doctor, dietician and nurse will decide if you need building up. This may be needed if you are
malnourished through weight loss. If you are going for neck or stomach surgery you may benefit from a
special type of nutrition called immunonutrition. This means giving special nutrients to try to boost
your immune system to help you to recover better. Speak to your doctor and dietician about this
before your surgery.
Follow the advice of your nurse about clearing your bowels and fasting.
➤ Chemotherapy
Chemotherapy can affect normal cells as well as cancer cells. It can affect cells in your gut and
bowel. This means at times you may lose your desire for food or be less able to eat. Eating problems
due to chemotherapy can include:
Taste and smell changes
Loss of appetite
Sore mouth or throat
Nausea and vomiting
Diarrhoea
Constipation
Weight gain or loss
These problems can vary and depend on the drug, dosage and your own response to it. Usually these
problems clear up once treatment ends or soon after.
Eating tips before chemotherapy
Bring a light meal or snack with you. Some hospitals may offer food and drink to you.
Eat something before treatment. Most people find a light meal or snack goes down well.
If you are taking chemotherapy tablets, follow the instructions about whether it’s best to take them
before or after eating, or with food.
Probiotic foods
Probiotic foods should be avoided if you are having chemotherapy. For example, ‘live’ or ‘bio’ yoghurts
and drinks. These foods contain live bacteria and could make you sick, especially if your white cell
count is low. Ask your nurse and dietician for more advice.
Radiotherapy
Radiotherapy may cause eating problems if an area of the body linked to eating and digestion has
been treated with radiotherapy. How severe any eating problems are depends on the area being
treated and for how long.
Treatment of head and neck may cause:
Dry mouth
Sore mouth
Sore throat
Difficulty swallowing
Taste and smell changes
Dental problems
Treatment of lung, oesophagus or breast may cause:
Loss of appetite
Nausea and vomiting
Difficulty swallowing
Indigestion
Increased phlegm (spit)
Treatment of stomach or pelvis may cause:
Loss of appetite
Nausea and vomiting
Diarrhoea
Cramping
Bloating
Fatigue and appetite changes may also affect you during treatment. You may feel too tired to shop,
prepare or eat food. After treatment, some of these problems may take longer to clear up. Talk to your
dietician for advice about your situation.
Eating tips before radiotherapy
Eat something at least 1 hour before treatment.
Bring foods or snacks to eat or drink on the way home.
Eat small frequent meals with fluids if you are having eating problems.
Biological therapy
Biological therapies use your immune system to fight cancer cells. Because your immune system is
working harder, it can affect your desire or ability to eat.
Common eating problems are:
Loss of appetite
Dry mouth
Sore mouth
Taste and smell changes
Nausea and vomiting
Diarrhoea
Weight loss
Being too tired to eat due to fever and aching muscles
Some of these eating problems go away after the first few doses of the drug or once treatment is over.
If your blood count is low, see page 45 for more about food safety.
Hormone therapy
Some types of hormone therapy can affect your appetite and change how your body deals with fluids.
It can cause:
Increased appetite
Excess fluids in your body (fluid retention)
These problems usually go away once treatment is over.
How can I build myself up?
During diagnosis, your nurse will talk to you about your eating habits. He or she can discuss any
recent weight loss as well. This will include checking your weight and height. You can also talk about
any eating problems you have or have had or any situations where you find it hard to eat. If you live
alone or need someone to prepare food, it can be arranged before you go home.
Building yourself up
If you are underweight, have lost weight unintentionally or have a poor appetite, you may need to build
yourself up.
Your doctor, nurse or dietician may advise you to follow a diet high in protein and energy (calories) to
help you to build up your strength. This will help you to deal with the effects of cancer and treatment.
You should also be less prone to infection.
Severe weight loss
Sometimes severe weight loss (cancer cachexia) can happen due to cancer itself or its treatment. This
is where there is severe loss of appetite, weight loss, loss of strength and muscle mass. If this
happens, there are ways to improve it. Your dietician and nurse will discuss these with you. See page
38 for more details.
What foods contain energy and protein?
Carbohydrates a good source of energy
Fats-high in energy
Proteins – help your body to repair itself after illness or treatment and fight infection
Vitamins and minerals – help your body to use the foods you eat
Talk to your doctor or dietician before taking any vitamin or mineral supplement, as it may interfere
with your treatment.
Increasing energy and protein
Here are some ways to increase your levels of energy and protein.
1. Eat more nutritious snacks and meals during the day. For example, eat six times a day.
2. For extra energy and protein, add the following to your food:
Butter or margarine
Milk
Cream
Cheese
Dressings, sauces and gravies
Honey, jam and sugar
3. Talk to your doctor, nurse or dietician about nutritional supplements. For example, build-up
drinks.
Nutritious snacks high in calories and protein
Baked potatoes with beans,
Cheese, tuna, crème fraiche
Breakfast cereal – hot or cold
Beans
Cheese
Crackers
Creamy soups or broth
Custards
Dips made with cheese or yoghurt
Hot chocolate
Ice cream
Milk puddings
Milkshakes
Mousse
Muffins or scones
Nuts
Omelette
Quiche
Sandwiches
Scrambled eggs
Smoothies made with yoghurt
Creamy soups or broth
Yoghurt or fromage frais
Build-up drinks and products
There are other ways to help you if you are not getting enough calories and protein from your diet.
You can get ‘build-up’ drinks to give you nourishment. These are known as nutritional supplements.
Most are high in protein and have extra vitamins and minerals. These drinks should not replace your
food but be taken alongside your other food as a supplement if you cannot eat well.
There are many types of drinks available to suit your taste and to help with particular problems.
Some are milky, some are yoghurt- or milkshake-style drinks and some are fruity. Some are just
‘shots’, others are bigger drinks.
Some have extra benefits like added fibre, fish oils to improve severe weight loss (cachexia) or
ingredients to help wound healing.
If you have problems swallowing, there are also puddings and powders to thicken food or drinks.
Over time the protein and calories in these drinks can help you put on weight. Also, your energy levels
may improve and make you feel better.
Your dietician will tell you which ones are suitable for you. Some build-up drinks are not suitable if you
have diabetes, kidney failure or other medical disorders.
You can buy build-up drinks in pharmacies and some supermarkets, or your doctor may prescribe
them for you.
Sample meal plans
Here are some sample meal plans that are high in protein and energy. They may give your ideas on
how to plan your meals for the day.
Remember to eat often if you have eating difficulties. Set aside a little time every 3 hours to eat
something. For snack ideas, see the centre pages of this booklet.
Breakfast
Fresh pineapple
Boiled egg on toast with butter-add lots of full-fat butter to toast
Lunch
Cream of mushroom soun-add a dollop of cream and herbs to the top
Bread roll with butter -add full-fat butter to rol
Fromage frais-choose full-fat variety
Dinner
Roast chicken
Jacket potato-add full-fat butter
Peas
Fresh fruit salad – add cream or ice cream
Breakfast
Fresh/tinned prunes
Scrambled eggs made with butter
Bread-fry the bread or add lots of full-fat butter
Lunch
Beans on toast-add cheese to the beans and full-fat butter to toast
Banana-add cream
Dinner
Lamb chop
Roast potatoes-coat the potatoes in oil before cooking
Carrots and parsnips-mash with butter and cream
Apple pie and custard
Breakfast
Fresh fruit juice
Porridge- made with full-fat milk, add some cream to porridge
Toast-add extra full-fot butter to toast
Lunch
Egg and cress sandwich -mix egg filling with full-fat mayonnaise
Yoghurt – choose thick and creamy or full-fat versions
Dinner
Mashed potatoes- add grated cheese or full-fat butter
Grilled/baked fillet of cod-add fresh herbs and olive oil
Green beans
Sherry trifle-add double cream
What if I can’t eat?
Most cancer patients can get all their nutrients from their diet, or from their diet and nutritional
supplements. If you’re not getting enough nutrition this way, your doctor and dietician can decide to
give you nutrients another way. They can be given through a feeding tube or straight into a vein.
➤ Tube feeding
The need for tube feeding will depend on your type of cancer or surgery and your general health. After
major surgery to the digestive system, you may not be able to eat normally at first. You may receive
nutrients through a tube passed into your nose, stomach or small bowel for a short while. Nutrients
can also be given directly into your stomach using a PEG tube.
Tube feeding can also be done if there is serious weight loss, swallowing difficulties, or when not
enough nutrients are taken.
➤ Feeding into a vein
In some cases, feeding may need to be given directly into a vein. This is called total parenteral
nutrition (TPN). TPN is used if your gut is not working properly or cannot be used for feeding. For
example, if there is a blockage in your bowel or a large amount of bowel has been removed during
surgery.
Your dietician will talk to you about special feeding if you need it.
Eating problems during treatment
Some of the common eating problems are listed here, with some advice about how to manage them.
Ask your dietician, doctor and nurse for more advice, if you need it.
Most of these problems go away once treatment has ended or soon afterwards. Others like dry mouth
from radiotherapy may be permanent.
Depending on the type of surgery you have, it may take some time for other eating problems to clear
up.
Poor appetite
Make the most of your appetite when it’s good. Eat when and what you want
Take small meals and snacks about every 2-3 hours.
Take snacks high in calories and protein.
Keep snacks handy. Try cheese and crackers, sandwiches, muffins or scones.
Use a smaller plate for your meals. Large portions can be off putting if your appetite is small.
Eat slowly and chew your food well.
Take plenty of drinks like milk, juices and soups.
Try build-up drinks, which have a balanced mix of nutrients for when it’s hard for you to eat food.
Special high-calorie drinks can help to keep your strength up. Talk to your dietician about suitable
one’s for you. Your doctor can also give you a prescription for these drinks.
Take only small sips while eating, as drinking might make you full.
Encourage your family to eat together and make mealtimes relaxing and enjoyable.
Take regular exercise, if you can, as it may help your appetite. Fresh air can help too.
Talk to your doctor about medications to help other problems, like constipation, nausea, pain or other
side-effects of treatment, if they affect your appetite.
Taste and smell changes
Eat foods that appeal to your taste buds and smell good.
Keep your mouth clean by rinsing and brushing-it may improve the taste of foods.
Eat food cold or at room temperature, if smells bother you.
Hold off eating foods that no longer appeal to you. Try them again some days or weeks later as you
might enjoy them again.
Flavour foods with onion, garlic or herbs like mint and basil, if you find food tasteless.
Marinate meat, chicken or fish to help the flavour.
Try small-sized tasty sandwiches.
Rinse your mouth with tea, saltwater or baking soda to help clear your taste buds before eating.
Drink plenty of fluids.
If liquids leave an unpleasant taste in your mouth, try drinking decaffeinated tea or coffee.
Eat fresh fruit and vegetables rather than canned ones, if possible.
Try chewing fresh or tinned pineapple before meals to get rid of bad tastes.
Use plastic utensils if you have a metallic taste while eating.
Sore mouth, gums or throat
Take sips of fluids like water often. Drink through a straw if your mouth is painful.
Eat soft, moist food like omelettes, scrambled eggs, mashed potatoes, cream soups, natural yoghurt,
milkshakes, stews, puddings.
Moisten dry or solid foods with sauces or gravies.
Purée or liquidise foods, for example, fruit and vegetables, in a blender to make them easier to
swallow.
Take cold foods and drinks like ice cream to soothe your mouth.
Take care with the following as they can make a sore mouth or throat worse:
Pickled, salty or spicy foods
Rough food, like crispy bread, dry toast or raw vegetables
Alcohol and tobacco
Citrus juices, like orange, lemon, lime, grapefruit or pineapple
Mouthwashes that contain alcohol, or acidic ones.
Take nutritious fluids like special build-up drinks and milkshakes and desserts like yoghurt, ice cream
or custard. Eating foods high in protein and calories will quicken healing.
Keep your mouth fresh and clean. Try sucking on mango or pineapple chunks, but avoid them if they
sting.
Rinse your mouth often with a salt and baking soda mouthwash. Add 1 teaspoon of baking soda and 1
teaspoon of salt to 1 pint of warm water.
Use special mouthwashes and gels often. Ask your nurse and doctor about safe ones to use.
Use a soft toothbrush. Put it into a container of warm water to soften the bristles.
Ask your doctor and nurse for painkillers if your mouth is painful. They may prescribe some antiseptic
or local anaesthetic gels or lozenges.
Visit your dentist regularly. He or she can give you advice about caring for your mouth and special
mouthwashes.
Dry mouth
Take sips of fluids like water often. Sucking ice cubes or ice pops may help too.
Drinking milk can help to protect your teeth. It is also a good source of protein and calories.
Eat soft moist food. Moisten your food with sauces or gravy
Rinse your mouth regularly, especially before and after meals.
Avoid the following as they can dry out your mouth:
Salty and spicy foods
Alcohol and caffeine
Mouthwashes that contain alcohol or acidic ones..
Take care with chocolate, pastry and freshly baked bread as they may stick to the roof of your mouth.
Use special mouthwashes, gels and moisturisers often. For example, products that contain saliva
enzymes. Your doctor or pharmacist can advise you about products to try.
If you have thick saliva, rinse your mouth often with a baking soda mouthwash. Add 1 teaspoon of
baking soda to 1% pints of water.
If your mouth has a bad taste due to dryness, rinse it before meals or suck on pineapple chunks.
Brush your teeth after every meal or snack. Use a soft toothbrush. Put it into a container of warm
water to soften the bristles.
Stimulate the flow of saliva with sugarless gum, boiled sweets or pastilles.
Keep your lips moist with a lip balm.
Difficulty swallowing
Eat your favourite foods but soften them with sauces and gravies, where possible.
Try eating soft, liquid foods like soups, broths, milkshakes, custards, natural yoghurt. But vary them so
you don’t get bored. Make sure soups and broths have potato, meat or fish in them for extra
nourishment.
Thickened liquids can be easier to swallow. Your speech and language therapist can advise you on
how to alter your foods.
Chop up meat and vegetables finely for stews or casseroles.
Blend or liquidise cooked foods.
Eat small, frequent meals.
Sit up as straight as possible for all your meals Try to remain seated upright for 20-30 minutes after
eating
Take build-up drinks, which are high in calories and protein Your dietician can advise you about these
and your doctor may prescribe them.
Drink at least 6 to 8 cups of fluid each day.
Ask your doctor to refer you to a speech and language therapist for special eating techniques.
Indigestion
Try to eat small frequent meals instead of large ones.
Sipping some drops of peppermint oil in hot water may help to relieve any discomfort
Herbal teas like mint or liquorice may help.
Avoid fizzy drinks, alcohol, spicy foods, pickles and citrus fruits.
Talk to your doctor or pharmacist about antacid medications that may help.
If indigestion is worse at night, avoid eating or drinking for 3 to 4 hours before bedtime.
Sit up after eating
Feeling full
Eat smaller meals often.
As you begin to feel less full, gradually increase the amounts of food and the time between meals.
Avoid foods high in fibre to prevent you feeling full very quickly. For example, large portions of fruit and
vegetables, wholegrain rice and pasta and wholemeal bread.
Don’t drink large amounts of liquids, especially fizzy drinks, just before mealtimes.
Nausea (feeling sick)
If you have nausea during radiotherapy or chemotherapy, avoid eating for 1-2 hours before treatment.
Drink clear liquids to prevent getting dehydrated.
Take plenty of nourishing fluids if you miss a meal or two.
Take fluids in between meals, as they may fill you up when eating.
Eating little and often may help. Eat slowly and chew food well.
Rest after your meals.
Eat before you get hungry, as hunger can make nausea worse.
If you are sensitive to the smell of hot food, try bland, cold foods.
Try the following foods and drink as they might help: -Fizzy drinks like mineral water, ginger ale, or lemonade -Cold foods like yoghurt, desserts, boiled potatoes, rice, noodles, breakfast cereal or cheese -Dry food like toast, scones, crackers or breakfast cereals. This can help in the morning before you get
up-Bland foods like breakfast cereal, bread or toast, soup and crackers, yoghurt, milk puddings,
scones or sandwiches -Herbal teas like mint
Avoid the following foods, as they may make nausea worse: -Fatty, greasy or fried foods -Spicy foods -Very sugary foods
-Foods with a strong smell.
Try foods containing ginger, such as ginger ale or tea, ginger nut biscuits, ginger cake or fresh ginger in
hot water.
If you have severe nausea, avoid your favourite foods. You may end up hating them after severe bouts
of nausea.
Ask a friend or family member to cook your meals if food smells affect you.
Ask your doctor and nurse about any anti-sickness medication you could take. Take them as advised.
Relaxation exercises, acupuncture or meditation can sometimes help to prevent nausea.
Vomiting
Don’t eat anything until the vomiting has stopped and is under control.
When the vomiting is under control, try small amounts of clear liquids like water.
Carry on taking small amounts of liquid as often as you can keep them down.
When you can keep down clear liquids, try a full liquid diet or a soft diet.
Ask your doctor and nurse about any anti-sickness medication you could take. Take them as advised.
If you get sick shortly after radiotherapy or chemotherapy, avoid eating for 1-2 hours before and after
treatment.
A rest after meals may help prevent vomiting
Relaxation exercises or acupuncture can sometimes help to prevent vomiting
Cramping
Eat and drink slowly, Small mouthfuls and chewing well can help.
Avoid food and drink that can cause wind or cramps like beer, beans, cabbage, garlic, spicy foods and
sugar-free gum and sweets made with sorbitol.
Let fizzy drinks go flat before drinking them.
Herbal teas like mint or liquorice may help.
Gentle exercise like walking can ease cramps.
Bloating
Avoid gassy foods like beans, brussels sprouts, onions, celery, carrots, raisins, bananas, prune juice,
apricots and wheat germ.
Avoid fizzy drinks and beer.
Eat and drink slowly and chew your food well.
Don’t skip meals.
Eat 4 to 6 small meals spread out over the day. Avoid large meals.
Add fibre to your diet slowly. For example, small amounts of vegetables, fresh and dried fruits, and
whole grains. Fibre may make bloating worse for some people.
Try not to talk while eating.
Avoid chewing gum and sucking on hard sweets.
Don’t smoke
Talk to your doctor and nurse to see if your medication or lactose intolerance is causing the bloating.
Ask your doctor or nurse if any over-the-counter preparations can help.
If you wear dentures, check with your dentist that they fit properly.
Exercise regularly if you can. Get at least 30 minutes of exercise each day.
Diarrhoea
Drink plenty of fluids to replace what you lose with diarrhoea. Take liquids 30 minutes to 1 hour after
your meal and/or between meals.
Eat small amounts of food during the day instead of three large meals.
Avoid high-fibre foods temporarily. These include bran, wholegrain cereals, nuts and seeds, bears and
peas, dried fruits, raw fruits and vegetables.
Your doctor may prescribe something to control the diarrhoea. Take this as advised.
➤ Healthy Lifestyle and Cancer Prevention
In terms of disease incidence, the numbers of individuals affected with cancer each year are
staggering. Cancer is the second leading cause of death in the United States, with one in two
Americans receiving a cancer diagnosis in their lifetime. In 2007, approximately 1.5 million new cases
and 559,650 deaths related to cancer are estimated to occur among Americans. Overall cancer
incidence is slightly higher in men than in women. After excluding common skin cancers, men most
commonly have prostate cancer (29%), followed by colorectal and lung cancer. For women, the most
common cancers diagnosed are breast (26%), lung (15%), and colorectal cancers (10%). Lung cancer
rates were historically higher in men but are now comparable in men and women.
Cancer accounts for an estimated one in four deaths in the United States, with overall 5-year survival
estimates approximating 66%. Advances in early detection and treatment have led to increased
survival rates, with the cancer survivor population currently estimated at approximately 10.5 million
individuals in the United States. Unfortunately, this progress has produced a large population of
individuals who present unique, and largely unaddressed, healthcare needs. Cancer survivors have
elevated risk for second cancers and numerous comorbidities acquired during their treatments
including weight gain, loss of bone and muscle mass, depression, cognitive loss, and decreased
mobility. This population represents one of the largest groups of health-motivated people for whom
clinical prevention messages are likely to be adopted.
Elevated risk for many of the common cancers (breast, colon, and prostate) has been linked to a
number of diet-related factors that range from poor nutrient status (i.e., low fruit/ low vegetable
intake) to the adverse effects of chronic excess energy intake (i.e., overfed/sedentary state). The
consistent finding across studies that cancer rates are lower among physically active/healthy-weight
persons has raised the issue of energy balance to a forefront in nutrition and cancer prevention. This
issue has become particularly important, given the growing incidence of obesity and inactivity among
people living in the United States and more industrialized countries.
This article will review the current evidence on the role of energy balance, nutrition, and lifestyle in
cancer prevention. Furthermore, proposed biological mechanisms of action thought to mediate the
risk modification of exposure to chronic positive energy balance also are presented. Finally, practical
information for making positive changes in lifestyle behaviours’ thought to be important in cancer risk
reduction will be provided.
Cancer is a Multistep Progressive Disease Process
To fully appreciate the complex role of diet in cancer prevention, an overview of the multistep process
leading to cancer development is warranted. As shown in the Figure, cancer does not develop
overnight; it is a disease that results from decades of insult to healthy cells that over time, and with
repeated insult, suffer undesirable changes and a growth advantage. Cancer cells also develop the
capacity to “escape” from repair or removal by a healthy immune system. The “path” to cancer is
thought to involve a stepwise progression originating with an initial event where cells are genetically
damaged, perhaps related to diet (high fat, dietary carcinogens, etc.) or some environmental factor
(UV light, smoking, radiation, etc.), and become “initiated.” Most initiated cells are routinely removed
or repaired by the immune system; however, on occasion, an initiated cell escapes these protective
mechanisms provided by the immune system and undergoes further damage, eventually resulting in
the development of cancer. This change in cells from healthy to cancer is called carcinogenesis and
encompasses several specific steps labelled as follows: initiation, promotion, progression, and
cancer.
Dynamic & Complex Influences of diet on the multistep process of carcinogenesis (Diagram)
Currently Recommended Cancer Nutrition and Physical Activity Preventive Measures
The American Cancer Society recently released updated dietary and physical activity guidelines for
cancer prevention. The current guidelines support the following:
Maintaining a healthy body weight throughout life
Adopting a physically active lifestyle
consuming a healthy diet with an emphasis on plant food sources
If you drink alcoholic beverages, limiting consumption
Of interest, these guidelines now emphasize the important role of body weight in reducing cancer risk
and suggest that maintaining a healthy body weight throughout adult life may be the single most
important behavioural approach to reducing risk for disease. For example, a woman reporting a body
weight of 130 lbs. At age of 18 years should maintain a weight between 130 and 143 lbs. Throughout
adulthood (thus controlling body weight to within 10% of early adult weight). Yet, despite this
recommendation and the “weight” of evidence that supports these recommendations, weight gain
throughout adulthood is well documented among Americans.
Importance of Healthy Body Weight Throughout Life
According to the National Center for Health Statistics, 65% of U.S. adults over the age of 20 are
overweight, with 30% of those considered to be obese. Obesity, particularly increased abdominal
obesity, is associated with increased risk for the development of reduced insulin sensitivity,
predisposing to the development of metabolic syndrome, cardiovascular disease, diabetes, and some
cancers. Most epidemiological studies support a role for obesity as a risk factor for endometrial
(39%), oesophageal (12%), kidney, and colon cancers (25%). For colorectal cancers, the effect of
obesity as measured by body mass index (BMI) seems limited to the colon with no effect in the
rectum, stronger in the proximal colon, and stronger in men than in women. In the case of hormonal
cancer, a BMI above 30 kg/m² at age of 30 years has been associated with a significant increase in risk
for developing hormone-related cancers including breast, ovarian, and uterine cancers. For breast
cancer, obesity, but more specifically, adult weight gain of 20 kg after age of 18 years, has been most
consistently shown to increase risk of postmenopausal breast cancer and is now considered an
established risk factor. Unlike postmenopausal breast cancer, premenopausal breast cancer has not
been associated with obesity or higher BMI. Premenopausal disease, which occurs earlier in life, also
tends to be more aggressive, suggesting that the factors contributing to risk are more likely to be
related to genetic background and/or significant exposures to cancer-promoting factors at
“vulnerable” time points in life when the breast/mammary gland is exposed to higher levels of growth
factors such as insulin and estrogen (in utero, early life, before puberty).
Evidence also has suggested that those adolescents who carry the BRCA1 and 2 familial breast
cancer gene mutations, while highly likely to develop breast cancer with age, may delay onset of
disease by as much as 12 years if they practice a physically active lifestyle and control their body
weight. Data on the relationship between obesity and prostate cancer are more inconsistent and
complex than those for breast and colon, with obesity most consistently associated with elevated risk
for more advanced disease at diagnosis.
➤ Physical Activity and Cancer Prevention
One of the most relevant findings in studies of cancer risk factors is the protective role of physical
activity for many of the common cancers, a protective effect which is related to a wide range of
biological mechanisms. With the exception of skin cancer, where sun exposure and physical activity
are strongly linked, regular physical activity has been associated with a 20% to 50% reduction of risk
for cancers of the uterus, colon, and breast. For breast cancer, the evidence for a protective effect of
physical activity is strongest for those cancers occurring after menopause, similar to obesity. Unlike
colon and breast cancer, limited evidence suggests that physical activity, particularly higher vigorous
activity, is associated with lower risk of more aggressive and fatal forms of prostate cancer.
In general, the protective effects of increasing levels of physical activity have been shown regardless
of the type of physical activity undertaken-recreational or occupational. To put the effective dose into
perspective, in a large study of physical activity conducted in 413,044 participants of the European
Prospective Investigation into Nutrition and Cancer, the level of physical activity required to achieve a
20% to 25% risk reduction for colon cancer translated to approximately 1 hour per day of vigorous
physical activity (metabolic equivalent [MET] = 6) or 2 hours per day of moderate-intensity physical
activity (MET 3). More recent analyses from the large Nurses’ Health Study showed protection against
recurrent disease when breast cancer survivors participated in regular, moderate-level, physical
activity for 30 minutes five times per week or 9 MET-hours per week. For colorectal cancer survivors,
the exercise dose required to reduce recurrence risk was approximately double (18 MET-hours per
week).
Although studies are limited, the benefits of regular exercise do seem to be strongest for those
individuals who maintain a healthy weight and for those individuals with lower energy consumption.
These data suggest important joint effects of physical activity and healthy body weight as primary
means of cancer prevention.
Of interest are data that support a protective role for physical activity early in a young woman’s life
(adolescence). Physical activity seems to have a favourable effect on the breast during development.
And, activity protects against adult weight gain and metabolic and hormonal factors associated with
breast cancer risk. Regardless, these data support the need for early counselling on lifelong
behaviours to reduce risk of breast and other cancers an important message that could be integrated
into general paediatric practice and school-based physical education programs.
Current American Cancer Society Guidelines specifically recommend that adults engage in physical
activity of moderate to-vigorous intensity for at least 30 minutes and preferably 45 to 60 minutes 5 or
more days of the week. This should be above usual activities such as walking to and from parking lots,
meal preparation, dressing, and the like. Maintaining an energy expenditure that controls body weight
within a healthy range is paramount to reducing cancer risk.
Several intervention trials have been conducted to evaluate the efficacy of select approaches to
enhance daily physical activity and thus reduce cancer risk, mostly targeting the cancer survivor
population. In general, cancer survivors report significant fatigue in relation to cancer treatments,
particularly radiation therapy-concern that is commonly expressed even several years after treatment.
Thus, early promotion of physical activity is essential for people diagnosed with cancer. Clinicians
should discuss the importance of a physically active lifestyle early in the treatment plan and reinforce
the need to remain active during and after therapy at on-going clinic visits. There is no clear evidence
that one type of activity is advantageous over another in this setting, although walking is commonly
used in clinical trials, and some research suggests that pedometers can be efficacious in goal setting
and longer-term maintenance of a physically active lifestyle. Cancer patients frequently experience
sarcopenia or loss of muscle mass, related to treatment, and this adverse outcome can be reduced
with regular physical activity during treatment. Specifically. Weight-bearing exercises and strength
training can promote retention of lean body mass and bone mass that also has been shown to be
adversely impacted by cancer treatment.
Tips for Enhancing Physical Activity and Energy Expenditure Daily
Physical activity
Take the stairs
Wear a pedometer
Park car at a distance when shopping or going to work
Walk daily with friend or pet
Walk during the lunch hour
Form work walking club
Sign up for local walking event to raise funds for important causes
Join a hiking or outing club
Cycle to work
Treadmill to your favourite music
Lift hand weights while watching television
Swim with a friend
Increase energy expenditure
Stand up during meetings
Eat small frequent meals
Carry small weights in your pockets
Drink caffeinated green tea, black tea, or coffee
Consume hot and spicy foods
Healthy Lifestyle and Cancer Prevention
Numerous nutrients and bioactive food components (BAFCs) have been shown to increase or
decrease cancer risk. Much of the evidence for protective associations has resulted from
epidemiological evidence where eating practices within a given population are evaluated against
cancer rates yielding an estimation of risk. Despite intuitive and biological evidence that diet plays a
role in cancer risk, much of the evidence remains inconsistent, and when diet has been shown to be
protective, risk estimates indicate relatively small protective effects. There are several major
limitations to assessing associations between diet and cancer risk including capturing the correct
exposure period, lack of accurate reporting of dietary intake, and quite simply, the complexity of the
human diet. These factors are particularly problematic in case-control studies where “cases” have
already been diagnosed with disease and are asked to recall their eating patterns before diagnosis.
➤ Vegetables and Fruit: BAFCs
Existing evidence is inconsistent in regard to the relationship between vegetable and fruit intake and
cancer risk. Although a large number of case-control studies (where people are asked about their
dietary habits after they have been diagnosed with cancer) have supported a protective association,
most cohort studies (where self-report of diet is collected before a cancer diagnosis) suggest that
commonly reported intake levels in study populations show no significant association. When
protective effects are shown, they tend to be on the order of a 10% to 20% reduction in risk,
suggesting that an increase in vegetable and fruit consumption alone is unlikely to have a significant
impact on disease incidence. One explanation for the lack of a significant protective effect is that
intake of vegetables and fruit may be insufficient, particularly in terms of upper levels of intake
needed to modify risk.
It is the BAFCs, such as carotenoids, as well as others such as polyphenols, resveratrol,
monoterpenes, and the like, found in plant foods that have been proposed to be of greatest
importance in reducing cancer risk. Research has included primarily cell culture models in which
cancer cells are exposed to select compounds at variable doses and epidemiological research in
which dietary intake of such compounds (or foods rich in BAFC) is evaluated in the context of cancer
events.
Alcohol
Folic acid supplementation has been associated with increased risk for adenomatous polyp
recurrence and thus may be detrimental after initiation. UNK indicates unknown association or lack
thereof, +, an association has been demonstrated; 1, unequivocal, O, no association shown.
Food Sources of Cancer-Protective Nutrients and BAFCS (Table)
Role of Energy Intake
Recent animal studies suggest that an energy or caloricrestricted diet is protective against the
development of tumours. In controlled animal feeding studies, a reduction in energy intake of 30% to
50% results in a marked and significant reduction in tumor production. The biology behind this
protective effect of energy restriction is not clearly understood but may have to do with the reduced
oxidative burden on the host or lower exposure to the tumor-promoting effects of insulin and insulin
like growth factor (IGF). It is well known that the metabolism of food (and the carbohydrates, fat, and
protein therein) increases oxidative stress, particularly if the diet is higher in fat content. This may
explain, to some extent, the phenomena of reduced risk in relation to reduced intake. The magnitude
of caloric restriction needed to achieve the same benefit in humans is unknown, and adverse effects
of nutrient deficiencies that may arise as a result of severe caloric restriction and impact on muscle
and bone health also are unknown. Thus, it is more prudent to promote energy balance and healthy
balanced diets to achieve lower growth factor and oxidative stress exposures.
Biological Mechanisms of Cancer Preventive Activity
Several dietary constituents demonstrate multiple bioactive properties resulting in activities that
reduce cancer risk. These include direct effects of dietary compounds to enhance the ability of the
cell to self-destruct (apoptosis), stop growth of damaged cells (cell cycle arrest), provide antioxidant
protection to the cells, alter hormone levels, activate special enzymes that detoxify the body of select
compounds that have been associated with cancer development, and favourably change the levels of
insulin/insulin-like growth factor to reduce cancer risk and to reduce inflammation. Inflammation
Inflammation is a long-standing suspect component in tumour formation. For the common cancers, it
is increasingly acknowledged that low-level chronic inflammatory states may contribute to the
development (initiation) and growth (promotion) of tumors, and this may explain the protective role of
non-steroidal anti-inflammatory agents (such as aspirin) at multiple organ sites. When evaluating the
role of inflammation in cancer, researchers commonly measure chemicals in the blood such as C
reactive protein and/or interleukin. If either of these markers is present at high levels in the blood, it
suggests that some inflammation is present in the body, and on a long-term basis, high levels of these
chemicals could place a person at a higher risk for developing cancer. The observed association
between obesity/inactivity and cancer risk may be related to chronic exposures associated with pro
inflammatory chemicals called cytokines. Visceral (central body) adiposity, in particular, is marked by
elevated levels of several inflammatory compounds that are known to be released from fat cells. The
lists given below has several foods and/or spices that have been shown to reduce inflammatory
biomarkers in human studies. Although most have not been investigated in controlled clinical trials
enrolling cancer patients, studies in “healthy” individuals support the notion that integration of these
foods/spices into the daily diet holds potential for controlling inflammation. Furthermore, the addition
of these foods/spices to standard anti-inflammatory medications may offer promise of enhanced
anti-inflammatory (therapeutic) response, potentially reduced medication requirements, and
avoidance of associated toxicities of anti-inflammatory medications.
Food/Spices with Anti-inflammatory Properties
Anthocyanins -berries, cherries, and pomegranate
Capsaicin-chilli peppers
Cinnamon
Garlic
Ginger
Green tea
Omega-3 fatty acids (salmon, sardines, herring, tuna, flax, and canola)
Turmeric/curcumin
Oxidative Stress
The role of oxidative stress in cancer etiology has been hypothesized for decades, yet no longitudinal
human studies exist that demonstrate that cumulative high oxidative stress increases risk for cancer.
Furthermore, the capacity for select dietary constituents to modify oxidative stress levels has been
demonstrated, and patients diagnosed with cancer have demonstrated elevated levels of oxidative
stress biomarkers. Extensive animal and cell culture studies support a major role for oxidative stress
as a primary mediator of DNA damage in cells and change in gene expression; thus, it is reasonable to
accept a major role for oxidative damage in cancer causation.
Food Sources of Antioxidant Nutrients and BAFCs
Citrus
Berries
Cranberries
Cherries
Melons
Green leafy vegetables
Yellow-orange vegetables
Tomato-based foods
Cruciferous vegetables
Red wine
Green tea
Brazil nuts
Oils such as olive oil
Seeds
Dark chocolate
Insulin-IGF Hypothesis
Epidemiological and animal studies provide consistent evidence that chronic elevations in blood
levels of insulin (known as hyperinsulinemia) may be a contributory factor for cancer in humans. In
the “Insulin Hypothesis” put forward by Giovannucci et al., chronic hyperinsulinemia is proposed to
Increase the bioactivity of insulin-like growth factors and insulin binding proteins that can be
measured in the blood and have been shown to promote growth of cancer cells. The major
determinant of insulin-associated chemicals is genetic background and more modest influences of
diet and physical activity. Severe caloric restriction is one of the main behaviour modifications that
reduces IGF-1 levels and may explain why animals placed on low calorie diets have lower tumor rates.
The interplay of diet, physical activity, obesity, metabolic syndrome (insulin resistance), and cancer
risk is an area of active cancer prevention research. Numerous similarities between risk factors for
diabetes, heart disease, and a number of common cancers including age, inflammation, central
adiposity, physical inactivity, high intake of saturated fats and refined sugars, and disturbances in
insulin regulation has led to the suggestion that the metabolic changes associated with adiposity,
principally insulin resistance, are risk factors for some of the common cancers. Many of these
metabolic disturbances are reversible with lifestyle and diet modifications offering a safe and well
supported strategy to reduce cancer and other chronic disease burdens in the population.
General Criterion Used in the Definition of Metabolic Syndrome
Waist circumference of 940 inches for men and 935 inches for women
Triglyceride concentration of 9150 mg/dL H
HDL cholesterol of G40 mg/dL for men and G50 mg/dL for women
Q130/Q85 mmHg or on hypertensive medication
Fasting glucose level of Q100 mg/dL
Adult Treatment Panel (ATPIII) of the National Cholesterol Education HDL indicates high-density
lipoprotein.