Oxygen free radicals and antioxidants: a review.

In 1989, nearly 43% of deaths in the United States were due to some form of cardiovascular disease, and 23% were caused by cancer. Thus, two of every three people in this country die from either cardiovascular disease or cancer. Based on both experimental and epidemiological evidence, investigators believe that free radicals play a critical role in the development of both diseases. Low levels of antioxidants, which increases free radical activity, are clearly associated with an increased risk of these diseases. This link has led to the conclusion that use of antioxidant vitamin supplements to scavenge free radicals could potentially decrease the risks of cancer and cardiovascular disease. Results from numerous studies to date have been very promising, although a true protective or preventive causal relationship has not yet been established. Numerous primary and secondary intervention trials currently underway should more definitively assess the role of antioxidants in disease prevention. In the interim, many people feel the evidence is now strong enough to begin supplementation on their own. The pharmacist is in a position to advise patients on the safe and moderate use of antioxidants. The antioxidants discussed in this article are relatively non-toxic, with the exception of vitamin A. The possible benefits of vitamin A are better achieved with the use of beta-carotene. Megadose antioxidant supplementation does not appear to provide any additional benefit beyond what a more moderate supplement can provide and should therefore be discouraged. Taking a trace mineral with antioxidant potential is generally a waste of money, provided the patient is not initially deficient in the element.(ABSTRACT TRUNCATED AT 250 WORDS)