Cooking methods, carcinogens, and diet-cancer studies.

A neglect of natural, preservative, and cooking-induced carcinogens or mutagens in food, along with a neglect of dietary patterns during the first portion of a person's lifetime, may be responsible for the many conflicting epidemiological reports dealing with dietary factors and cancer. From animal and occupational studies, we know that the two most important factors in the study of cancer are the dose of carcinogen and allowance for a long latent period. Most of the recent nutrition and cancer studies have ignored both factors. Some bile acids or other endogenous factors may be influenced by diet and may act as cancer-promoting agents, but promoting agents cannot be studied in the absence of knowledge about, or control of, the cancer-initiating events with which they must interact.