Some vitamin E benefits questioned

A decade ago, vitamin E earned a reputation as a potent heart disease- and cancer-preventing antioxidant. Studies showed a lower risk of heart disease in people who took vitamin E supplements or got lots of the vitamin from their diets, and animal and lab research suggested that the vitamin prevented fat from building up in blood vessels. The essential, fat-soluble vitamin is crucial for healthy eyes and skin and a robust immune system. But the latest research findings suggest that vitamin E supplements might hold little promise for most people who want to keep heart disease, cancer and stroke at bay.

Uses: Proponents of vitamin E recommend taking it to prevent heart disease, stroke, cancer (particularly prostate cancer), cataracts, Alzheimer’s disease and Parkinson’s disease.

Dose: Federal guidelines recommend 30 international units per day. (One IU of vitamin E is equal to 0.67 milligram.) Vitamin E comes in natural and synthetic forms, both well absorbed by the body. The vitamin is abundant in fruits, leafy greens, whole grains, nuts and vegetable oils, so most people get more than enough to stay healthy. In the majority of studies investigating the disease-prevention potential of the vitamin in humans, subjects were given hundreds of IUs per day.

Precautions: Long-term use of high-dose supplements (providing 400 to 800 IU per day or more) can cause nausea, headaches and fatigue, among other conditions. Some research hints that vitamin E may increase bleeding, but findings haven’t been consistent.

Research: Last week, the Journal of the American Medical Assn. published results from the Women’s Health Study showing that, for most women, vitamin E did not prevent heart attacks, stroke or cancers of the lungs, breast or colon. However, the vitamin did seem to lower risk of heart attack in women over 65. The study looked at the effects of a daily dose of 600 IU of vitamin E in close to 40,000 women age 45 and older. Several studies have linked the vitamin to a lowered risk of prostate cancer in men, but experts are awaiting a definitive answer from the so-called SELECT trial, a National Cancer Institute-supported study that is investigating the effects of selenium and vitamin E supplements in more than 35,000 men. There’s no good evidence that vitamin E supplements can prevent Parkinson’s or degenerative eye diseases, such as cataracts. Some studies have linked the vitamin to decreased risk of Alzheimer’s disease, but findings are still far from conclusive.

Dietary supplement makers are not required by the U.S. government to demonstrate that their products are safe or effective. Ask your healthcare provider for advice on selecting a brand.

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-- Elena Conis