Preventing Cancer

The American Institute for Cancer Research conducted an evidence based review of the world literature and issued its first report in 1997. The National Cancer Institute followed with evidenced-based overviews of cancer prevention. The World Health Organization International Agency for Research on Cancer recently published a series of handbooks on cancer prevention in relation to dietary factors. 

The recommendation remains to consume between 20-35% of calories from fat, emphasizing heart-healthy monounsaturated and omega-3 fats, while limiting saturated and trans fats. Fat is more calorie-dense than carbohydrates and protein, and eating more high-fat foods is likely to promote weight gain. The best strategy to lower the risk for cancer and heart disease is to consume a diet high in a variety of fruits, vegetables, whole grains and beans but low in saturated and trans-fats, maintain a healthy weight, and stay physically active.

The NCI Cancer Commission of the National Academy of Sciences published a report in 1982 that provided available evidence and subsequent conclusion that most major cancers are influenced by dietary patterns. In addition, the Diet, Nutrition and Cancer spurred various national recommendation for the development of research agendas on investigation of the diet-cancer link, including expansion of basic research on molecular and cellular nutrition, identification of foods and dietary constituents that may alter cancer risk, and elucidation of the mechanisms by which these dietary constituents modulate cancer risk.

Cancers are largely preventable and the most effective methods for reducing risks are to avoid tobacco use, to consume an appropriate diet and to limit exposure to occupational and other environmental carcinogens. 30-40% of cancer cases worldwide are preventable by feasible dietary means. There is sufficient evidence in humans that avoidance of weight gain has a cancer-preventative effect with regard to cancers of colon, breast (postmenopausal), endometrium, kidney (renal cell) and esophagus (adenocarcinoma).

Consumption of fruits and vegetables lowers the risk of gastrointestinal cancers (mouth and pharynx, esophagus, stomach and colorectal). Vegetables and fruits should provide 7% or more of total energy annually; and consumption of 400-800g (15-30oz) or 5 or more servings per day of a variety of vegetables and fruits are recommended. You should have either 5-9 servings per day or 400g/d of fruit/veggies, including fiber.