What are the most important characteristics of a diet that minimizes cancer risk? The results of animal studies suggest that the single most powerful and consistent dietary influence on carcinogenesis (the ability of cancer to reproduce) is simply energy or calorie restriction. Thus the diet should be low in fat. Various studies have related fat intake to cancer incidence. Animals fed high-fat diets develop cancers more readily than animals on low-fat diets.

Protein intake should be relatively low, since high levels of protein consumption are associated with an increased risk of many diet-responsive cancers, the Western diet is excessively rich in protein. By contrast, dietary fiber intake, which is far too low in the usual Western diet, should be increased.

Processed sugar, by contrast, should be restricted. Sugar, for example, increases the mouth-to-anus transit time and increases the fecal concentration of bile acids; this may explain its association with colon cancer. Also, while complex carbohydrates appear to be protective, sugar intake is directly associated with the risk of breast cancer.

All these dietary goals can be met or approached by simply increasing the consumption of fruits and vegetables – which are protective against all the major cancers – while decreasing the consumption of red meat. Generally low in fat and protein and high in fiber, fruit and vegetable consumption can substantially reduce cancer risk. Five servings daily is the absolute minimum recommendation; yet, in the United States, only one in eight adults say they meet that goal. (A serving is, for example, one half cup of chopped raw or cooked vegetables, three-quarters of a cup of juice, or a piece of fruit.)

Smoked, pickled, and salt-cured foods, as well as meats (such as hot dogs) that have an artificial red color, and meats that are broiled or otherwise subjected to high-temperature cooking, should also be minimized. Sources of nitrites, nitrosamines, and polycyclic aromatic hydrocarbons, which cause cancer in animals, their consumption has been associated with the risk of gastric cancer as well as certain other malignancies such as brain tumors and leukemia.

So who’s ready for some fruit?