Healthy eating for cancer survivors

After treatment, cancer survivors should follow recommendations for cancer prevention.

DIET-related chronic diseases have now become significant causes of death in many countries, including the developing world. Cancer is one such chronic disease. In many of its forms, cancer is a disease that can cause great suffering and claims many lives.

However, cancer is not an inevitable consequence of ageing, and people’s susceptibility to it varies. There is abundant evidence that food and nutrition, physical activity, and body composition are individually and collectively important modifiers of the risk of cancer. This does indeed mean that at least in principle, most cancer is preventable.

Recognising this, I have highlighted the prevention of cancer, especially through appropriate food and nutrition practices, in a series of NutriScene write-ups over the past year. I had relied on recommendations contained in the World Cancer Research Fund (WCRF) expert report on Food, Nutrition, Physical Activity and the Prevention of Cancer released in November 2007 (www.dietandcancerreport.org/). In addition, I had also relied on the Hong Kong WCRF recommendations for cancer prevention booklet (www.wcrf-hk.org/).

I had highlighted eight general recommendations and one special recommendation of the WCRF report in previous write-ups. All these recommendations dealt with lowering risk and prevention of cancer.

In this article, I will discuss the last of this series of recommendations. This recommendation does not deal with prevention of cancer, but focuses on healthy eating for cancer survivors. I find this an extremely important topic to highlight. There is a great deal of misconception regarding the dietary and nutritional needs of cancer patients and survivors.

Healthy eating is vital for cancer survivors

Cancer survivors are people who are living with a diagnosis of cancer, including those who have recovered from the disease.

Treatment for many cancers is increasingly successful, and so there are many more cancer survivors. Furthermore, cancer survivors are living longer and may live long enough to develop new primary cancers or other chronic diseases. It is therefore extremely important for cancer survivors to adopt appropriate healthy eating practices and an active lifestyle.

There are just too many people out there providing nutrition advice, some of which are really dubious, and others can even be harmful. There are patients who tell me they are afraid of drinking milk or taking eggs as these will make the cancer cells multiply even faster. There are others who eat only fruits and vegetables because they believe they are healthy foods. Such myths about food and nutrients can result in the cancer survivor not obtaining much needed nutrients.

There are also promotions for dubious products that supposedly can “treat” cancers. These include various antioxidant supplements that are supposed to be able to kill cancer cells. It will be very sad indeed if patients forgo conventional medical treatment and dietary advice for such products or practices.

WCRF recommendation for cancer survivors

Upon reviewing all available evidence, the WCRF expert panel concluded that:

·There is growing evidence that physical activity and other measures that help us maintain a healthy weight, such as a balanced diet, may help to prevent cancer recurrence, particularly for breast cancer.

·However, the evidence is not yet clear enough to be able to make any specific recommendations for cancer survivors as a whole, or for those who are survivors of any specific form of cancer.

·The recommendations can also reduce the risk of other chronic diseases like heart disease and diabetes, so they can be beneficial to cancer survivors for this reason.

Anyone who has received a diagnosis of cancer should receive specialist nutritional advice from an appropriately trained health professional. This includes all cancer survivors, before, during, and after active treatment.

Once treatment has been completed, if the person is able to do so (and unless otherwise advised by a qualified professional), aim to follow the cancer prevention recommendations for diet, healthy weight maintenance, and physical activity. These recommendations have been highlighted in previous articles here. I will summarise these recommendations in the next section.

The above recommendations are generally appropriate, but may not be applicable for specific groups, e.g. people who are currently undergoing treatment for cancer. These patients are likely to have special nutritional requirements. In these cases, it is best to ask an appropriately trained health professional (e.g. a dietitian or a doctor) for advice. This is also true for cancer survivors whose treatment have affected their ability to eat or digest some foods – for example, patients who have undergone a gastrectomy (partial or full surgical removal of the stomach) or a colostomy (a surgical procedure that involves connecting a part of the colon onto the anterior abdominal wall, leaving the patient with an opening on the abdomen called a stoma).

Healthy eating and active living for cancer prevention (and cancer survivors)

Recommendation 1: Be as lean as possible within the normal range of body weight.

·Ensure that body weight through childhood and adolescence growth projects towards the lower end of the normal BMI range at age 21.

·Maintain body weight within the normal range from age 21.

·Avoid weight gain and increases in waist circumference throughout adulthood.

Recommendation 2: Be physically active as part of everyday life.

·Be moderately physically active, equivalent to brisk walking, for at least 30 minutes every day. Brisk walking can be incorporated in occupational, transport, household, or leisure activities.

·As fitness improves, aim for 60 minutes or more of moderate, or for 30 minutes or more of vigorous, physical activity every day.

·Limit sedentary habits such as watching television.

Recommendation 3: Limit consumption of energy-dense foods and sugary drinks that promote weight gain.

·Consume energy-dense foods (more than about 225–275kcal per 100 g) sparingly

·Avoid sugary drinks (i.e. drinks with added sugars)

·Consume “fast foods” sparingly, if at all (The term “fast foods” refers to readily available convenience foods that tend to be energy-dense and consumed frequently and in large portions).

Recommendation 4: Eat mostly foods of plant origin.

·Eat at least five portions/servings (at least 400g) of a variety of non-starchy vegetables and fruits of different colours every day.

·Eat relatively unprocessed cereals (grains) and/or pulses (legumes) with every meal.

·Limit refined starchy foods.

·People who consume starchy roots or tubers as staples need to ensure intake of sufficient non-starchy vegetables, fruits, and pulses (legumes).

Recommendation 5: Limit intake of red meat and avoid processed meat.

·People who eat red meat should consume less than 500g a week, very little if any to be processed. (Note: Red meat refers to beef, pork, lamb, and mutton from domesticated animals, including that contained in processed foods; processed meat refers to meat preserved by smoking, curing or salting, or the addition of chemical preservatives, including that contained in processed foods.)

Recommendation 6: Limit alcoholic drinks

·If alcoholic drinks are consumed, limit consumption to no more than two drinks a day for men and one drink a day for women.

·Children and pregnant women should not consume alcoholic drinks.

Recommendation 7: Limit consumption of salt and avoid mouldy cereals (grains) or pulses (legumes).

·Avoid salt-preserved, salted, or salty foods; preserve foods without using salt.

·Limit consumption of processed foods with added salt to ensure an intake of less than 6g (2.4g sodium) a day.

·Do not eat mouldy cereals (grains) or pulses (legumes).

Recommendation 8: Aim to meet nutritional needs through diet alone.

·Dietary supplements are not recommended for cancer prevention.

Cancer survivors should pay attention to meeting their nutritional needs. There are no secret recipes or magic formulas for cancer survivors. They need not rely on expensive products and practices to stay healthy after completing the required treatments.

Healthy eating and active living recommendations for the prevention of cancers are generally applicable for survivors too. Seek help from an appropriately trained health professional.