Eating well after cancer treatment
This information has been written for you if you are living with or after cancer and want to know more about a healthy diet. It explains why diet is important and has tips on how to eat well and maintain a healthy body weight.
After experiencing cancer, many people want to make positive changes to their lives. Taking steps to live a healthier lifestyle is often a major part of these changes.
This information aims to help you think about what changes you may want to make to your life and help you put them into practice. There are also answers to some commonly-asked questions about diet and cancer.
This information doesn’t cover the dietary problems that can be caused by cancer or its treatments, such as a weight loss, eating difficulties or poor appetite. There's more information and advice about this in our diet and cancer section. You can also contact our cancer support specialists for more information and support.
The relationship between diet and cancer
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Experts think that up to 1 in 4 cancers in developed countries may be linked to diet. There’s a lot of research being done at the moment into what types of food may affect our risk of developing cancer. But, despite this, we still don’t understand exactly how diet influences the risk of cancer.
There are many reasons for this uncertainty – mainly to do with the complex nature of cancer itself and of our diets. Eating habits vary greatly from person to person. Our diets are made up of many types of foods, which in turn are made up of thousands of different substances.
Some of these substances may increase our risk of cancer but others may protect us. And the influence on what we eat, and our risk of cancer, is likely to take many years or even decades to have an effect. So trying to find out how diet affects cancer risk is complicated.
For now, we do know about the types of food that can help to keep us healthy. And we know that a balanced diet helps us to maintain a healthy body weight, which can help to reduce the risk of some cancers.
Can diet reduce the risk of cancer coming back?
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People often ask if what they eat can reduce their risk of the cancer coming back. At the moment this is the subject of a lot of research. There is some early evidence from studies in breast and bowel cancer that diet may make a difference to the chances of cancer coming back.
But there still isn’t enough clear information to make precise recommendations about what a person with a particular type of cancer should eat. In general, cancer experts recommend following a healthy balanced diet.
For most people the greatest benefit to their health is likely to come from a combination of factors, including diet, weight control and regular physical activity, rather than from making any one particular change to their diet.
Your healthcare team (this includes your GP, doctors and nurses) are the best people to advise you what, if any, lifestyle measures you can take that may help to reduce your risk of cancer coming back.
Why a healthy diet is important
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Eating a balanced diet is one of the best choices you can make for overall health. Many people find that making this positive choice helps to give them back a sense of control. It can also help you feel that you’re doing the best for your health.
Eating well and keeping to a healthy weight will help you to regain your strength, have more energy and have an increased sense of wellbeing. It can also help to reduce the risk of new cancers, heart disease, stroke and diabetes.
After cancer treatment, some people have a higher risk of developing other health problems such as diabetes, heart disease or osteoporosis (bone thinning).
If you’ve been told that you may be at increased risk of any of these conditions, it’s especially important to follow a healthy diet to help to prevent them.
A healthy eating guide
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Before making changes to your diet, it can help to talk to your GP or cancer specialist. For most people a healthy balanced diet includes:
lots of fruit and vegetables
plenty of starchy foods such as rice, bread, pasta and potatoes
wholegrains rather than refined processed grains
some protein-rich foods such as meat, fish, eggs and pulses (beans and lentils)
some milk and dairy foods
just a small amount of foods high in fat, salt and sugar.
Fruit and vegetables
Fruit and vegetables are a good source of many vitamins and minerals, and a great source of fibre. They should make up about a third of the food we eat each day. But most of us don’t eat enough of them.
Research suggests that people who eat diets high in fruit and vegetables may have a lower risk for some types of cancer (cancers of the mouth, gullet and bowel), and may also have a lower risk of heart disease.
You should aim to eat at least five portions of fruit and vegetables a day.
A portion is:
3 heaped tablespoons of vegetables
a dessert bowl of salad
1 average-sized fruit, like an apple, pear or banana
2 smaller fruits, like apricots or plums
a slice of larger fruits, such as melons or mangoes
a handful of small fruits, like cherries or berries
a glass of fruit juice (150ml). Fruit juices can only count as one portion a day however much you drink.
Different coloured fruits and vegetables contain different nutrients. Eating a variety of fruit and vegetables of different colours will help to make sure you are getting a wide range of valuable nutrients.
Starchy foods and fibre
Starchy foods such as bread, chapati, cereals, rice, pasta, yams and potatoes are a really important part of a healthy diet. They are a good source of energy and a major source of fibre, iron and B vitamins in our diet. Starchy foods should make up about a third of the food we eat.
Foods rich in fibre are a very healthy choice but most people don’t eat enough. Try to include a variety of fibre-rich foods in your diet such as wholegrain bread, brown rice, oats, beans, peas, lentils, grains, seeds, fruit and vegetables.
High-fibre foods are more bulky. They help make us feel full, so we are less likely to eat too much. Fibre helps to keep bowels healthy and prevent constipation. And soluble fibre, found in foods such as oats, beans and lentils, may help to reduce the amount of cholesterol in the blood. Eating a diet with plenty of high-fibre foods can also help reduce the risk of bowel cancer.
If you eat red meat and processed meat several times a week, try to cut down. Try to eat more fish, chicken, turkey, beans or lentils instead.
Several studies suggest that eating lots of red and processed meat can increase the risk of developing bowel cancer and prostate cancer.
Red meat is beef, pork, lamb and veal. Processed meats include sausages, bacon, salami and tinned meats.
The greatest increase in risk seems to be for people eating two or more portions of red or processed meat (about 160g) a day. People who eat less than two portions per week (about 140g) seem to have the lowest risk.
Eating meat that is cooked at high temperatures, used in frying and barbecuing, may also increase the risk of some cancers. This may be because when meat is burnt or charred it produces chemicals which can damage normal cells.
No link has been found between eating poultry meat such as turkey and chicken and the risk of developing cancer.
Having some fat in our diet helps us to absorb vitamins A, D, E and K, and provides us with essential fatty acids that we can’t make ourselves. But most people in the UK eat too much fat.
Foods that are high in fat are also high in energy (calories), so eating lots of fat can make you more likely to put on weight.
There are different types of fat:
Saturated fat can raise the levels of cholesterol in the blood and increase the risk of heart disease. Foods that are high in saturated fat include cheese, butter, ghee, burgers, sausages, samosas, biscuits, pastries, cakes and chocolate.
Unsaturated fat helps to reduce blood cholesterol levels. Omega 3 fatty acids, a type of unsaturated fat found in oily fish (mackerel, salmon, trout and sardines), may help to prevent heart disease.
But there are also some potential health risks of eating too much oily fish because of contamination with chemicals such as dioxins. So the UK Food Standards Agency recommend that children and women who may become pregnant eat a maximum of two portions a week and men and women past childbearing age eat no more than four portions a week.
Other good sources of unsaturated fat include sunflower, olive and vegetable oils, nuts and seeds.
It’s important to try to eat less fat and choose foods that contain unsaturated fats instead of saturated.
What you can do to eat less fat:
Eat more fish and chicken (with the skin removed), rather than red meat.
Choose lean cuts of meat and trim off all the fat you can.
Eat less fried food – bake, grill, steam or poach food instead.
Choose lower-fat dairy products when you can.
When you’re shopping, check the labels for fat and saturated fat and choose lower fat options.
Put more vegetables and beans and a bit less meat in stews and curries.
Try vegetarian recipes more often.
Cut out or reduce the number of fatty takeaways (such as burgers, curries and kebabs) that you eat.
Avoid snacks which are high in fat, such as pastries, crisps and biscuits.
Cut down on salt
High salt diets can increase the risk of stomach cancer. Reducing your salt intake will help you to lower your blood pressure and your risk of heart disease and stroke. Most people in the UK eat much more salt than they need. The maximum recommended intake of salt for adults is 6g per day. That’s about a teaspoonful.
When we think about how much salt we eat we usually think of how much we add to our food or cooking. But about 75% of the salt we eat comes in processed foods such as bread, bacon, snacks and convenience foods.
You can find out how much salt is in processed foods by checking the labels. If there’s more than 1.5g salt per 100g (or 0.6g sodium), the food is high in salt. Low salt foods contain 0.3g salt or less per 100g (or 0.1g sodium).
When you’re buying bread, cereal and ready meals, compare the amount of salt in different types and choose the lower ones.
Try not to add salt to your food.
Add herbs or black pepper to pasta dishes, vegetables and meat instead of salt.
Marinate meat and fish before cooking to give them more flavour.
Alcohol has been linked with an increased risk of developing some types of cancer. As little as 1 unit a day can increase the risk of mouth, gullet (oesophagus), breast and bowel cancers.
The more alcohol someone drinks the greater the risk. But drinking small amounts of alcohol may help to reduce the risk of heart disease, at least in middle-aged people.
Current sensible drinking guidelines recommend that:
men drink less than 3 units of alcohol per day, or 21 per week
women drink less than 2 units per day, or 14 per week.
One drink isn’t the same as one unit of alcohol.
Half a pint of standard strength (3–4%) beer, lager or cider contains 1 unit.
Half a pint of stronger (5%) beer, lager or cider contains 1.5 units.
A standard glass of wine (175ml), often called a small glass in pubs and bars, contains 2 units.
A large glass of wine contains 3 units.
A single measure (25ml) of spirits contains 1 unit.
Drinking large quantities of alcohol in one session (binge drinking) is thought to be worse for your health than drinking a small amount each day. It’s also recommended that people have one or two non-drinking days each week.
Maintaining a healthy body weight
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It’s not a good idea to be either underweight or overweight. Eating too much can make you overweight, which can lead to ill health such as heart disease, high blood pressure or diabetes. Not eating as much food as your body needs can also affect your health.
If you are underweight, or find it difficult to eat enough to maintain your weight, you can find helpful advice in our diet and cancer and recipes from Macmillan Cancer Support sections.
Many people in the UK are heavier than the recommended weight for their height. And unfortunately, certain kinds of treatment for cancer, such as hormonal therapies or steroids, can cause weight gain. Losing weight can be difficult but keeping a healthy body weight is one of the best ways to reduce your risk of cancer.
Being overweight increases the risk of many types of cancer including cancers of the large bowel (colon and rectum), kidney, womb, oesophagus (gullet) and breast cancer in women after the menopause.
There is also evidence that women who have breast cancer after their menopause may be able to reduce their risk of the cancer returning by maintaining a healthy body weight after treatment.
Try to keep your weight within the normal range for your height. Your GP can advise you on your ideal weight. If you’re concerned about your weight, get in touch with your GP or a dietitian for advice and support.
Be patient with yourself. Losing weight is a gradual process. It’s important to eat a balanced diet to make sure you get all the nutrients you need to keep your body healthy. It’s reasonable to aim to lose about 1kg (2lbs) a week.
Only eat as much food as you need.
Eat a balanced diet with lots of fruit and vegetables and less fat and sugar.
Be more physically active.
There’s information and advice about increasing your physical activity in the Exercise after cancer treatment section.
Commonly-asked questions about diet and cancer
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Should I take dietary supplements?
For most people, a balanced diet provides all the nutrients they need and taking large doses of vitamins, minerals and other dietary supplements isn’t recommended. But people who find it difficult to eat a balanced diet may benefit from taking a multivitamin and mineral supplement containing up to 100% of their recommended daily allowance.
Supplements may be beneficial in some situations, such as for people who aren’t able to absorb all the nutrients they need because of surgery for stomach cancer. People at increased risk of bone thinning (osteoporosis) may benefit from taking calcium and vitamin D supplements to help strengthen their bones.
Several studies have looked at whether using supplements can reduce the risk of certain cancers. But the results have been disappointing and in general the evidence is that taking supplements doesn’t reduce the risk of cancer. There is even evidence that taking high doses of some supplements can increase the risk of cancer in some people.
One study found that people who smoke were more likely to develop lung cancer if they took supplements of beta-carotene (a substance the body uses to make vitamin A). And the results of other studies suggest that high doses of beta-carotene and vitamin A supplements may increase the risk of getting cancers of the gullet and stomach.
It’s possible that some supplements may interfere with how cancer treatments work and make them less effective. So, if you’re currently having treatment for cancer it’s important to get advice from your cancer specialist before taking any supplements. They can advise you about which, if any, you should take, and which doses might be appropriate for you. They can also tell you about any possible side effects and interactions with other medicines.
What about ‘superfoods’?
There isn’t any scientific evidence for any one particular food being a ’superfood‘. The greatest benefit to your health is likely to come from eating a balanced diet that includes a wide and varied combination of foods.
There are many substances in fruits and vegetables that may potentially have anti-cancer properties but we don’t yet know this for certain, and we don’t understand which ones are most likely to help or how they work.
So instead of looking for a ‘superfood’ it’s better to aim for a ‘superdiet’ as recommended in healthy eating guidelines. This will help you to make sure you’re getting the widest possible variety of these substances. It will also make your diet more enjoyable and interesting and it will probably be cheaper.
Should I follow a dairy-free diet?
Many research studies have looked for a link between diets that are high in dairy products and cancer (in particular breast and prostate cancer). But these studies haven’t shown a clear link. Because of this, cancer experts don’t recommend following a dairy-free diet to try to reduce the risk of cancer.
Dairy products are an important source of calcium, which is needed for strong bones and may help to reduce the risk of bowel cancer. So, if you decide to follow a dairy-free diet you’ll need to make sure that you get enough calcium from other food sources such as tinned sardines and salmon (with the bones), dark green leafy vegetables (such as spinach) or fortified foods (such as some types of soya milk).
Does sugar feed cancer?
No. Sugar in your diet doesn’t directly increase the risk of cancer or encourage it to grow. But sugar contains no useful nutrients (apart from energy) and we can get all the energy we need from healthier sources. So, it’s best to limit the amount of sugar in your diet.
Do anti-cancer diets work?
There has been a lot of publicity about alternative diets for treating cancer over the past few years. Many dramatic claims for cures have been made. It’s understandable that people may be attracted to diets that seem to offer the hope of a cure. However, there isn’t good evidence that these diets can make a cancer shrink, increase a person’s chance of survival or cure the disease.
Some people get satisfaction from following these special diets, but others find them quite boring and even unpleasant to eat and time-consuming to prepare. Some diets may lack important nutrients or be unbalanced in other ways and may even be harmful.
It can be confusing to be faced with conflicting advice about what to eat, but most doctors and specialist nurses recommend a well-balanced diet and one that you enjoy, as described in this section.
If you’re thinking of making changes to what you eat you can get more advice from your doctor, dietitian or specialist nurse. They can offer you information and advice tailored to your particular situation. You can also contact our cancer support specialists for more information and support.
This section has been compiled using information from a number of reliable sources including:
Food nutrition, physical activity and the prevention of cancer: A global perspective. November 2007. World Cancer Research Fund.
A. Bloch et al. Eating well, staying well during and after cancer. 2004. American Cancer Society.