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What is the health value of carotenoid supplements?

Compared with the benefits of dietary carotenoids, thus far, studies on carotenoid supplements have yielded mixed results. In fact, certain carotenoid supplements may actually be harmful. Although dietary-intake studies indicate that foods rich in beta-carotene and vitamin A may lower the risk of many types of cancer, when it comes to supplements, the findings are decidedly less promising: Not only have a number of studies found beta-carotene supplements ineffective in protecting against cancer, but in some studies they’ve actually been shown to exacerbate cancer. In the Alpha-Tocopherol, Beta-Carotene Cancer Prevention Study, more than 29,000 male smokers were randomized to receive 20 milligrams of beta-carotene, 50 milligrams of alpha-tocopherol (a form of vitamin E), supplements of both or a placebo for five to eight years. Lung cancer incidence was 18 percent higher among the beta-carotene-supplement takers, with 8 percent more deaths. The Carotene and Retinol Efficacy Trial had similar results when those researchers provided their subjects with supplements of 30 milligrams of beta-carotene and 25,000 IU of retinyl palmitate (a form of vitamin A) or a placebo. In fact, this study was stopped when researchers realized that the subjects receiving beta-carotene had a 46 percent higher risk of dying from lung cancer.

Although large doses of dietary carotenoids in humans results in a yellowing of the skin (hypercarotenemia), this condition is not thought to be harmful in normal, healthy people.

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Important: This content reflects information from various individuals and organizations and may offer alternative or opposing points of view. It should not be used for medical advice, diagnosis or treatment. As always, you should consult with your healthcare provider about your specific health needs.