Antioxidants are substances that may protect cells from the damage caused by unstable molecules known as free radicals. Free radical damage may lead to cancer. Antioxidants interact with and stabilize free radicals and may prevent some of the damage free radicals might otherwise cause. Examples of antioxidants include beta-carotene, lycopene, vitamins C, E, and A, and other substances.
Five scientific studies done in the 1990’s about antioxidants give more insight. The studies examined the effect of beta-carotene and other antioxidants on cancer in different patient groups.The first large randomized trial on antioxidants and cancer risk was the Chinese Cancer Prevention Study, published in 1993. The trial investigated the effect of a combination of beta-carotene, vitamin E, and selenium on cancer in healthy Chinese men and women at high risk for gastric cancer. The study showed that the combination did indeed reduce the risk of gastric cancer.
A 1994 cancer prevention study entitled the Alpha-Tocopherol (vitamin E)/ Beta-Carotene Cancer Prevention Study (ATBC) demonstrated that lung cancer rates of Finnish male smokers increased significantly with beta-carotene and were not affected by vitamin E. Another 1994 study, the Beta-Carotene and Retinol (vitamin A) Efficacy Trial (CARET), also demonstrated a possible increase in lung cancer associated with antioxidants.
The 1996 Physicians’ Health Study I (PHS) found no change in cancer rates associated with beta-carotene and aspirin taken by U.S. male physicians.
Lastly the 1999 Women’s Health Study (WHS) tested effects of vitamin E and beta-carotene in the prevention of cancer and cardiovascular disease among women age 45 years or older. Among healthy women there was no benefit or harm from beta-carotene supplementation. Investigation of the effect of vitamin E is ongoing
The studies give odd and sometimes contradictory results about vitamin E and Beta-Carotene, but the studies on antioxidants are more consistent. Considerable laboratory evidence from chemical, cell culture, and animal studies indicates that antioxidants may slow or possibly prevent the development of cancer. Even still more recent studies have shown inconsistent results. Sometimes it’s hard to see if the correlation is what’s making something happen. For a good source of antioxidants, try acai berries.
