Diet, nutrition and cancer in Japan.

A number of epidemiological and experimental studies have revealed that dietary habits and nutrition are one of the major risk factors for cancer. Dietary habits and nutrition are related to cancer in various ways and many factors are involved in the development of cancer. These include large intakes of salted foods and pickled vegetables, and too low intakes of fresh vegetables and fruits which are known to be major risk factors for stomach cancer. A large intake of green-yellow vegetables is known to be a protective factor against cancer of the stomach, lung and some other sites. In Japan the westernization of dietary habits and nutrition may have contributed to the changes in the mortality of several kinds of cancers which have been observed in Japan in recent years. Further improvements of dietary habits and nutrition intake are important and will be effective for primary prevention of cancer.