Evaluation of the evidence on the role of tomato products in disease prevention.

During the last 30 years, research in the field of nutrition and chronic disease causation has led to exciting, significant progress in providing an understanding of specific risk factors and chemopreventive agents. The major health problems considered are cardiovascular diseases and the nutritionally linked cancers, including those in the stomach, colon, breast, prostate, ovary, and endometrium. The major elements considered were salt, type and amount of fat, and heterocyclic amines formed during cooking. Bran cereal fiber, as well as vegetables, fruits, and tea have been shown to inhibit the complex processes of initiation and development of these diseases. One aspect involved in initiation and development of both cardiovascular diseases and the cancers noted are abnormal oxidative processes leading to the generation of hydroxy radicals and peroxy compounds. In part, the protective role of vegetables, fruits, and tea is to provide antioxidant vitamins and specific polyphenols that display a powerful inhibition in oxidative reactions. Epidemiological studies as well as laboratory experimentation have yielded sound data and evidence in support of the fact that vegetables, fruits, and tea and specific antioxidants therein account mechanistically for inhibition. Geographic pathology has provided important data that populations with a regular intake of tomato products, such as in the Mediterranean region, have a lower incidence of the chronic diseases noted. The current Symposium is considering the varied mechanisms of action of tomato products in general, and one of the active principles, lycopene. Cooking is a factor in releasing the desirable antioxidants from tomatoes. Cooked tomato products may be preferable to the raw vegetable or juices derived from tomatoes bearing on absorption of the active principles. Optimally, absorption of lycopene, a highly lipid-soluble chemical, is improved in the presence of a small, but essential amount of oil or fat. Research in the field of nutrition and health has shown that monounsaturated oils such as olive oil or canola oil are most desirable, since such oils do not increase the risk of atherosclerosis, coronary heart disease, or the nutritionally linked cancers. The International Symposium on tea conducted in 1991 has provided worldwide interest in research on the beneficial effects of tea. It is now hoped that the present Symposium, dealing with another inexpensive and readily available food, tomatoes, will enhance interest in and funding for additional research, to underwrite future recommendations for possibly enhanced production and use of tomato-derived nutritional elements, with the goal of application to the prevention of major chronic diseases, the treatment of which is costly and often ineffective.