Definition

It appears more than ever, that there is a great deal of truth to the philosophy of eating fruits and vegetables to maintain optimum health. It is not only because of the nutrients they contain in the form of vitamins and minerals, also because of the chemicals found in these foods. Scientists continue to extensively study the nutrient quality and quantity of foods we consume. Although scientists are still not certain about the specifics, they’re beginning to close in on the healthful constituents of plant-based foods. In particular, they’re looking closely at two components: phytochemicals and antioxidants The goal is to determine precisely how and why these substances in fruits and vegetables can prevent or stop the development of tumors and cancer When animals are given vegetables and fruits before being exposed to carcinogen (cancer-causing agents), they are less likely to develop cancer. Although additional experimental data needs to be collected in humans, there is evidence to suggest that consuming generous amounts of fruits and vegetables plays an important role in preventing cancer.

Purpose

Phytochemicals, are plant chemicals that are naturally occurring substances in plants. Several hundred types of phytochemicals have been identified, but many more likely remain to be identified. Some examples include indoles in cabbage or cauliflower, saponins in.

peas and beans, genstain in soybeans and isoflavones in soy milk and tofu. Over the past 20 years, nutrition scientists have consistently found that individuals that eat greater amounts of vegetables and fruits have lower rates of cancer. It has been only recently that the mechanism(s) by which phytochemicals assist the body in resisting cancer have begun to be understood. The phytochemicals present in fruits and vegetables protect the body by stunting the growth of malignant cells. Investigators have only an inkling of how many phytochemicals exist and how they work. They are confident, however, that an individual can get a basketful of anti-cancer nutrients by mixing and matching at least five servings a day of fruits and vegetables with seven or more starchy or protein-rich plant foods such as grains, peas and beans, and potatoes.

Supplements containing vitamins and minerals can help an individual gain some of the benefits of these substances. However, vitamin and mineral supplements are not a total replacement for real food.

This is because vitamin and mineral supplements, though very beneficial, do not supply the thousands of phytochemicals that might be present in fruits and vegetables, according to the Cleveland Clinic Foundation in Ohio. For example, eating a sweet potato with its skin, which is a great source of both beta carotene and fiber, provide at least 5,000 phytochemicals that are not present in a beta carotene supplement. That’s an extremely important difference. Isolating a few compounds in a pill will not provide you with the hundred of protective benefits that plant food provide. The best advice is to obtain phytochemicals by eating a good variety of plant foods every day. Whether fruits and vegetables are consumed in raw or cooked form does not really matter with regard to phytochemical content. Even canned, frozen and juiced fruits and vegetables pack a phytochemical punch. However, raw or steamed vegetables would provide the best nutrient value.

The antioxidants found in fruits, vegetables, and other plant-based foods fight free radicals, which are compounds in the body that attack and destroy cell membranes. The uncontrolled activity of free radicals is believed to cause many cancers. Examples of antioxidants include carotenoids, such as beta carotene, lycopene, and vitamins C and E.

The carotenoids, in particular, which give fruits and vegetables their bright yellow, orange, and red colors, are now gaining recognition for their nutritional worth. Numerous studies have extolled the virtues of lycopene (the carotenoid that makes tomatoes red) in preventing prostate cancer. One such study at Harvard University found that men who include tomato products in their meals twice a week could reduce their risk of developing prostate cancer by one-third compared with men who do not consume tomatoes.

Other lycopene-rich foods, such as watermelon, red grapefruit, and guava, are now piquing the interest of researchers. Watermelon not only yields more lycopene per serving (15 mg in 11/2 cups) than raw tomatoes (11 mg per 11/2 cups), but it’s also a rich source of vitamins A and C.

Whether antioxidants can reduce the incidence of cancer is still uncertain at this point because of the lack of sufficient studies. However, research data obtained thus far indicates that antioxidants do appear to provide health benefits.

The National Cancer Institute estimates that roughly one-third of all cancer deaths may be diet related. Scientists have recently estimated that approximately 30 to 40% of all cancers could be averted if people ate more fruits, vegetables, and plant-based foods and minimized high-fat, high-calorie edibles.