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Beta-Carotene Pills Yield No Benefit, 2 Studies Find | |
| By Lawrence G. Proulx (c) 1996, The Washington Post If you're taking beta-carotene pills to improve your health, it seems you're behind the times. Like the 1994 study of 30,000 smokers in Finland, two studies in the May 2 New England Journal of Medicine failed to find any benefit from taking beta-carotene supplements. Beta carotene is one of about 500 yellow and red plant pigments called carotenoids. It is the raw material from which the body produces vitamin A, and it is also an antioxidant, a chemical thought to guard cells against destructive oxygen molecules called radicals. Orange and dark-green vegetables and fruits are generally rich in beta carotene. The first of the two studies was a test of 22,071 male physicians aged 40 to 84, half of whom took, while half did not, 50-milligram beta-carotene supplements every other day for 12 years. It was carried out by epidemiologist Charles Hennekens and his associates at Brigham and Women's Hospital and the Harvard School of Public Health in Boston. The two halves did equally well. "There were virtually no early or late differences in the overall incidence of malignant neoplasms (cancers) or cardiovascular disease, or in overall mortality," the researchers found. They concluded: "This large-scale, randomized trial among apparently healthy, well-nourished men demonstrated no statistically significant benefit or harm. ... Because of the long duration of the trial, these findings are particularly informative, and the large sample and narrow confidence intervals exclude even a small overall benefit or harm due to beta carotene with a high degree of assurance." The second study, by a team led by physician Gilbert Omenn at the Fred Hutchinson Cancer Research Center in Seattle, tested supplements of beta carotene with vitamin A on half of 18,314 smokers for an average of four years. They found somewhat more lung cancer in those taking the supplements, much as the Finnish study had, but no differences in other types of cancer. Along with earlier studies, they concluded, their findings "make it clear that there can be little enthusiasm about the efficacy or safety of supplemental beta carotene or vitamin A in efforts to reduce the burdens of cancer or heart disease in certain populations." In an editorial in the same issue, E. Robert Greenberg and Michael B. Sporn of Dartmouth Medical School in Lebanon, N.H., commented that these studies "should put to rest any remaining hopes that, for adults, beta-carotene supplements may be an effective means of lowering the risk of cancer and cardiovascular disease." The Boston team noted that "even though beta carotene (supplementation) is ineffective in preventing cancer and cardiovascular disease, other micronutrients may not be. For example, vitamin E supplementation remains promising as a preventive intervention." While research continues, the Seattle team remarked, "to reduce the risk of (lung cancer and coronary heart disease) we must rely primarily on three approaches: smoking cessation, prevention of smoking, and avoidance of occupational and environmental exposure to carcinogenic substances." And, "we still recommend the dietary intake of fruits and vegetables." | |