Diet and the prevention of cancer
According to Dr John Cummings and Dr Sheila Bingham from the MRC Dunn Clinical Nutrition Centre, Cambridge, around half of UK cancer deaths are due to tumours of the lung, bowel, breast and prostate. In this week's BMJ, they say that these cancers are virtually absent in many countries in the developing world, but increase in incidence within one or two generations when migrants move from low to high risk areas. Therefore, they say, many cancers common in Western populations can be attributed to environmental factors - which means that they should be largely preventable.
Diet is one of the most important lifestyle factors that has been estimated to account for up to 80 per cent of cancers of the bowel, breast and prostate. The authors highlight red and processed meats and alcohol as the highest risk foods and cite a diet rich in vegetables and fruit as the most protective. They stress that there is no evidence to suggest that high dose vitamin supplements can help to prevent cancer and these should be avoided. Other environmental factors known to affect susceptibility to cancer include: physical activity, reproductive and sexual behaviour, infection with hepatitis B or C viruses, infection with helicobacter and exposure to sunlight, ionising radiation and chemicals.
Cummings and Bingham conclude with five tips for reducing cancer risks: don't smoke; take regular exercise; don't be sexually promiscuous; avoid prolonged exposure to direct sunlight and avoid contracting hepatitis B and C viruses.
Contact:
Dr John Cummings, Head, Gut Group, MRC Dunn Clinical Nutrition Centre, Cambridge email:john.cummings@mrc-dunn.cam.ac.uk