Antioxidants are substances that are capable of counteracting the damaging, but normal, effects of the physiological process of oxidation in animal tissue. Antioxidants are nutrients as well as enzymes (proteins in your body that assist in chemical reactions). They are believed to play a role in preventing the development of such chronic diseases as cancer, heart disease, stroke, Alzheimer's disease, Rheumatoid arthritis, and cataracts. Why the Elderly Must Take Antioxidants Many researchers claim that elderly people, especially those who have reduced their food intake, frequent aspirin users, heavy drinkers, smokers, and people with impaired immune systems may benefit from taking antioxidant supplements daily. In terms of heart disease and stroke, it is possible that higher levels of antioxidants slow or prevent the development of arterial blockages, a complicated process involving the oxidation of cholesterol. Moreover, antioxidants may deter the collection of plaque on arterial walls. Exercise and Free Radicals Exercise in untrained individuals overwhelms defenses resulting in increased free radical damage. Thus, the "weekend warrior" who is predominantly sedentary during the week but engages in vigorous bouts of exercise during the weekend may be doing more harm than good. To this end there are many factors which may determine whether exercise induced free radical damage occurs, including degree of conditioning of the person, intensity of exercise, and diet. Because Free Radicals have one or more unpaired electrons, free radicals are highly unstable. They scavenge your body to grab or donate electrons, thereby damaging cells, proteins, and DNA (genetic material). The same oxidative process also causes oils to become rancid, peeled apples to turn brown, and iron to rust. Sources of Antioxidants! Consuming more antioxidants helps provide the body with tools to neutralize harmful free radicals. It's estimated that there are more than 4,000 compounds in foods that act as antioxidants. The most studied include vitamins C and E, betacarotene and the mineral selenium.