Dietary intervention and chemoprevention--1992 perspective

Diet, including excess or scarcity of specific foods and nutrients, is important in the etiology of 30-60% of a variety of cancers. Dietary changes may favorably affect cancer risk and incidence. This overview summarizes recommended dietary changes and their nutritional implications and considers the problems of selecting and implementing such a program and identifying and targeting appropriate populations and subjects.

Dietary changes that decrease the intake of fat and pickled/smoked foods, limit calorie intake and alcohol consumption, and increase the intake of fiber, fruits, and vegetables should help to decrease risk for cancers of the breast, colon, oral cavity, upper gastrointestinal tract, lung, and cervix. Micronutrients to increase include vitamins C, E, A, beta-carotene and other carotenoids, and folic acid. The diet should contain a variety of yellow-orange fruits and vegetables, green leafy and cruciferous vegetables, legumes, whole grains, low-fat dairy products, and lean meats, fish, and poultry. This diet must be adequate in proteins and minerals, palatable, affordable, and add to the quality of life. It is important that we target appropriate subjects and populations, modify foods, and design and fund research studies in areas of nutrient availability and metabolism and the biologic mechanisms of nutritional chemoprevention.

A program of nutritional intervention by sound dietary changes that is effective, safe, and acceptable in chemoprevention should be the cornerstone of a cancer prevention strategy starting now. Directions for future research are discussed.