Pills can't replace healthy living

Good diet and exercise, not vitamins, are key to fighting illness, experts point out

August 05, 2005|By Stephen Smith | By Stephen Smith,New York Times News Service

On the surface, it makes all the sense in the world: Since fruits, vegetables and fish contain loads of healthful nutrients, why not isolate those vitamins, put them in pills, and gobble them up? And wouldn't more be better?

Then we could just skip the strawberries, spinach and salmon, and let fistfuls of vitamin tablets provide a fortified shield of protection against cancer, heart disease and other ailments, right?

"It's a very plausible hypothesis," said Dr. JoAnn Manson, chief of preventive medicine at Brigham and Women's Hospital in Boston. "How-ever, when submitted to rigorous testing, it has not held up. ... It's an oversimplified view."

Three times in recent weeks, scientists writing in medical journals have attacked the notion that heavy-duty helpings of vitamins can thwart life-threatening illnesses. In some cases, they argued, excessive supplementation may even be harmful.

The way to live a long, healthy life, the researchers insisted, is not to pop lots of pills, but to eat a balanced, healthy diet.

For reasons that scientists have yet to figure out, the body processes vitamins differently when they arrive in food than in pill form -- probably because foods interact with each other in a way that may help nutrient absorption. So far, nutrition specialists said, scientists working in labs can't beat what nature does.

"What you can buy in a bottle doesn't come close to providing you with the wealth of benefits that come automatically when those nutrients are present in the form of food," said Linda Van Horn, a research nutritionist at Northwestern University in Chicago.

Nutrition advice, though, is never quite as simple as "take your vitamins" or, even, "don't take your vitamins." And, further complicating matters, the answer isn't the same for everybody.

Much of the recent criticism of vitamins has revolved around megadoses, which can be 10, 20, even 30 times stronger than the amount recommended for the daily diet.

But even multivitamins, which typically contain the recommended daily intake of a host of nutrients, are not universally accepted by nutritionists.

Alice H. Lichtenstein, a professor at Tufts University's Friedman School of Nutrition, said there's no evidence that multivitamins are hazardous -- but she said there's also no compelling proof that they do much. Other experts believe multivitamins can help restore nutritional equilibrium to a defective diet.

"If you look at what people eat -- and there have been many national surveys to look at levels of nutrients and foods -- there is a lot of deficiency," said Dr. Meir J. Stampfer, a professor of epidemiology and nutrition at the Harvard School of Public Health. "We're not talking about people with scurvy or rickets, but there are nutrients that large, substantial portions of the population are not getting," he said, including, vitamins B12 and D. And for some people whose extreme poverty keeps them from eating right, supplements can be life-savers.

Last year, vitamin sales in the United States totaled $6.9 billion, according to estimates from the Nutrition Business Journal, a market research and publishing firm. That's roughly the size of the bottled water industry.

But the promise of high-dose vitamin pills has been increasingly contradicted by gold-standard scientific research, Lichtenstein wrote in The Journal of the American Medical Association late last month.

For example, consider beta carotene. It was trumpeted as the ultimate cancer fighter. But researchers in one study showed that high doses of the nutrient, which the body converts to vitamin A, actually increased the chance that a smoker would develop lung cancer.

Then there's folate. Physicians still encourage women trying to get pregnant to take supplements that include folate, because of scientific studies showing it prevents birth defects. But recent findings have tempered hopes that folate would also help battle heart disease, and one study suggested that heart patients who took large amounts of folate after an operation to unclog their arteries, were more likely to get clogs again.

Two other medical reports released last month examined vitamins D and E. The vitamin D study, published in the Archives of Internal Medicine, found that it did not slow bone loss in older African-American women, as had been predicted.

And the vitamin E report, appearing in the Journal of the American Medical Association, concluded that for most women, large doses of vitamin E do nothing to prevent heart problems.

Still, even the president of the American Heart Association acknowledges just how seductive the healing promise of vitamins can be. Dr. Robert H. Eckel, of the University of Colorado, said he took vitamin E for a couple of years, based on those early reports hailing its disease-fighting properties. But when the more elaborate research results emerged: "I finally looked at the evidence and said, gee, this isn't worth taking."

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