Heart disease is still the number one cause of death in the US, but it is on the decline and may be overtaken by cancer by the end of the century. There is increasing evidence that diet may play a role in both types of disease. You can only eat one type of diet, and you may not know whether you should be more concerned about heart disease or cancer, so what should you do?

According to the latest set of recommendations published by the American Cancer Society (September 1996), the sort of diet that you’ve read about as being good for the heart is also good for preventing cancer. They propose that a good diet should be low in fat and red meat, high in fruits and vegetables, and with little alcohol. The Society also recommends maintaining a healthy weight and exercising regularly.

Although the recommendations look the same as the recommendations for preventing heart disease, the reasons for making them are very different. Red meat is thought to increase the risk of colon and prostate cancer; obesity may be associated with several types of cancer, including colon, prostate, uterus, and breast; and heavy alcohol consumption may be associated with breast cancer.

One area where the cancer and heart disease guidelines diverge is the question of nutritional supplements. The cancer guidelines state that there is no evidence that taking large doses of vitamins C and E or beta carotene confers any protection. It is now generally accepted that vitamin E does protect against heart disease.

The American Cancer Society also states that there is no evidence of any harm from most food additives, artificial sweeteners or coffee. Two additives that are questionable are nitrites, which could increase the risk of stomach cancer, and olestra, the new fat substitute, which could interfere with the absorption of cancer-protecting substances.