Recently, it has been confirmed that excessive accumulation of iron, common in meat-eating populations, may be a highly significant risk factor in the development of heart disease, although not as important as smoking. This is probably due to this transition metal being a generator of free radicals. Therefore, it is also a probable risk factor for cancer. Unless you have a demonstrated need for iron, it is a good idea to avoid supplements that contain it, although these studies were not done with iron supplements.

By careful lifestyle choices some of these free-radical sources can be avoided and others can be counteracted. By making these choices for yourself you can slow down the aging process, decrease the risk of cancer and heart disease and promote high energy and a vital, healthy feeling of well-being. One way to protect yourself from free-radical damage is to take dietary supplements. The chapters on the individual supplements contain more specific information.

We need extra supplies of those nutrients destroyed by toxins and those that help to prevent the harmful effects of these foreign chemicals. Specifically, vitamins A, C, E and beta-carotene; the trace minerals selenium and zinc; and accessory food factors, such as bioflavonoids and coenzyme Q10, all help to scavenge free radicals through antioxidant activity. They help prevent cancer, heart disease, premature aging and tissue degeneration. Many herbs also help in the fight against excess free radicals.

Destructive Agricultural Practices
Modern agricultural practices have adversely affected the quality of our food supply. Growing foods with methods designed to increase quantity, or to facilitate transportation and storage (such as the development of sturdy, square tomatoes) is often detrimental to their nutritional value. Nutritional value is rarely considered when developers play with the genetics of plants or soil modifications.

Soil quality has been degraded through modern farming methods. Most chemical fertilizers do not replace all of the minerals needed for human nutrition. Organic foods have been shown to have a higher nutritional value than conventionally grown foods. They are also free of the pesticides, herbicides and thousands of other risky chemicals that are added to foods during processing. There is also wide variation in the natural mineral content of the soil. For example, in northeastern states (and elsewhere) the soil has a very low selenium content. Selenium is important for protection from heart disease and cancer. In spite of a diet that includes foods from many geographic areas, research has shown that people living in regions with low soil selenium have a higher risk of cancer. Although selenium, as well as chromium and iodine, are essential for human nutrition, they are not required for growing healthy plants. They are rarely added to the soil for agricultural purposes.

Foods are often picked before they are ripe and allowed to ripen in transit, at the market or during home storage. They do not acquire their full complement of minerals and vitamins, which frequently increase greatly during the later stages of growth. In addition, transportation and storage of foods, whether in the market or at home, allows time for nutrients to deteriorate. Fruits and vegetables can lose significant amounts of vitamin C after 3 days in cold storage, and even more at room temperature. Dried fruits can also lose vitamins A, C and E if exposed to oxygen and light. This is not to say that stored foods are of no value, but the lower nutrient content increases the importance of taking supplements.