Evidence suggests that vitamins C and E, and beta carotene, a precursor to vitamin A, may reduce the risk of some forms of cancer, heart disease, strokes, cataracts, as well as slow the aging process. Although oxygen is vital to life, scientists are also finding this essential element may contribute to human aging and illness. When oxygen is metabolized or burned by the body, cells form byproducts called free radicals. Free radicals travel through the cell, disrupting the structure of other molecules and resulting in cellular damage. Such damage is believed to contribute to aging and various health problems.
Antioxidants protect key cell components from damage by neutralizing the free radicals.
In an effort to beef up bodily defenses to combat free-radical activity, scientists are studying the effects of increasing individuals' antioxidant levels through the diet and dietary supplements. Participants were given either a placebo or a dietary supplement containing one of seven vitamin-mineral combinations. Persons who received a daily dose of beta carotene, vitamin E and selenium had a reduced cancer rate of 13 percent. Much of the previous evidence was based on epidemiological studies of populations, which suggested an association between antioxidants and disease prevention but were not designed to reveal cause and effect relationships. The study involved 1,795 female nurses, each of whom had a history of heart attack, chest pain due to coronary disease, or treatment for a blockage in a coronary artery.