Cancer Prevention

Also known asCancer Risk · Preventing Cancer · Anti-cancer Diet · Cancer and Diet · 防癌 · 癌症预防

What it is

Cancer happens when cells grow out of control. About a third to a half of common cancers could be prevented by changes in lifestyle, and by vaccination and screening where available. The biggest controllable factors are smoking, alcohol, excess body fat, inactivity and the way we eat.

How food and lifestyle can help

The most consistent advice from cancer research groups is: stay a healthy weight, be physically active, eat mostly whole grains, vegetables, fruit and beans, limit red meat and avoid processed meat, limit sugary drinks and ultra-processed foods, and limit or avoid alcohol. Do not smoke.

Foods and nutrients to focus on

1. Whole grains, vegetables, fruit and beans at most meals, rich in fibre.
2. A variety of colourful vegetables and fruit.
3. Fish, poultry, eggs, tofu and other soya foods in place of red and processed meat.
4. Water, unsweetened tea or coffee as your main drinks.

Foods and drinks to limit

1. Processed meat (bacon, ham, sausages, salami, cured and smoked meats), classed as a cause of bowel cancer; and red meat, ideally no more than about 350 to 500 g (cooked weight) a week.
2. Alcohol: there is no safe level for cancer risk, so less is better.
3. Salt-preserved and pickled foods, including salted fish, and a lot of salt (sodium).
4. Sugary drinks, ultra-processed foods and charred or burnt meat.

Good to know

1. High-dose supplements do not prevent cancer, and beta-carotene supplements increase lung cancer risk in smokers. Aim to get nutrients from food.
2. Screening (breast, cervical, bowel and others, depending on your country and age) finds cancers early and prevents some; take it up when invited.
3. Vaccines against hepatitis B and HPV prevent liver and cervical cancers.
4. See also the pages on Colorectal Cancer, Breast Cancer, Liver Cancer, Stomach Cancer, Prostate Cancer, Lung Cancer and Nasopharyngeal Cancer.

When to see a doctor

1. A new lump, unexplained weight loss, blood in the stool, urine or phlegm, a cough or hoarse voice that lasts more than three weeks, a sore that does not heal, or a change in a mole.
2. You are due, or overdue, for screening.
3. You are being treated for cancer: ask your cancer team or an oncology dietitian before changing your diet or taking supplements.

This page is general information, not medical advice. If you have a medical condition or take medicines, check changes to your diet with your doctor or a registered dietitian.

WHO — Cancer, used for the main facts: https://www.who.int/news-room/fact-sheets/detail/cancer