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Vitamin E warning sounded
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(Victoria Times-Colonist, Nov. 11/04)
Study shows popular supplement may carry serious health risks
Sharon Kirkey
CanWest News Service
Thursday, November 11, 2004
Millions of North Americans take vitamin E because they think it will prolong their lives, but in fact it's increasing their risk of a premature death, researchers are warning. And the higher the dose, the higher overall risk of dying.
People who take more than 400 IU (international units) of vitamin E per day for more than a year are four to six per cent more likely to die prematurely from any cause than those who don't swallow the supplements, according to a study released Wednesday on the Annals of Internal Medicine Web site.
The increased risk may seem insignificant, but "if you apply it to the 25 per cent of the U.S. adult population taking vitamin E, five per cent increased risk can be a lot of people," says lead author Dr. Edgar Miller, an associate professor of medicine at the Johns Hopkins University School of Medicine.
"No one should take high-dose vitamin E," Miller says. Multivitamins are considered safer, because they typically contain only 30 to 80 IU of vitamin E.
The new research is based on a review of 19 studies, including two from Canada, comprising more than 136,000 patients.
Vitamin E is the most studied antioxidant in the world. Antioxidants prevent damage to cells by mopping up free radicals, toxic molecules the body produces when it burns sugar and fat. Some studies suggest vitamin E can help prevent the early stages of cancer by preventing DNA damage, but people pop the pills in the hope it will ward off everything from Alzheimer's to wrinkles. Many women take vitamin E to prevent breast tenderness.
The Johns Hopkins doctors warn the higher death rate in vitamin E users is an important public health issue -- and a dramatic departure from earlier findings.
In fact, when Miller first set out to review studies showing antioxidants protect against chronic diseases, everyone seemed to benefit at first glance, until he realized those taking vitamin E were dying faster than people on a placebo.
"We know they are dying more, but we don't know the specific reason why they are dying," said co-author Dr. Eliseo Guallar, an assistant professor of epidemiology at the Johns Hopkins Bloomberg School of Public Health.
Many of the studies didn't report the cause of death, or reported it inconsistently. Death from all causes includes deaths from "heart disease, strokes, cancers, accidents -- everything," he says.
However, the team suspects vitamin E may prevent the blood from thickening, increasing the risk of hemorrhagic strokes, or bleeding in the brain. One study showed an increased risk of hemorrhagic strokes among vitamin E users.
In high doses, vitamin E may actually "re-generate" free radicals, or disrupt the body's natural anti-oxidant system.
"Just knowing there is a problem is enough information to avoid these high-dose vitamins," Guallar says.
"I think people should use caution. Unless it's an extreme case where your vitamin E reserves are low, a multivitamin should provide enough vitamin E for your requirements," says Dr. Venket Rao, professor emeritus in the department of nutritional sciences at the University of Toronto and an expert on antioxidants.
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