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Extra Vitamin E: No Benefit, Maybe Harm
By Jane E. Brody, The New York Times
March 23, 2009
About three decades ago at a scientific conference on aging, just about every presenter was taking vitamin E, a nutrient with antioxidant properties that, it was thought, would slow the cellular ravages of age.
In subsequent years, many reports from observational and case studies suggested that vitamin E in daily doses far greater than recommended could help to stave off heart disease and stroke, various common cancers, dementia and Alzheimer’s disease, cataracts and macular degeneration, respiratory tract infections and a host of other serious and sometimes fatal health problems.
The logic was that an antioxidant like vitamin E protects cells from the damaging effects of free radicals, which are byproducts of metabolism and exposure to cell-damaging agents like sunlight, radiation and chemotherapy.
Ever hopeful for a magic elixir, millions of health-conscious Americans began self-dosing with amounts of vitamin E dozens of times greater than the recommended daily intake for this fat-soluble nutrient.
If only all those hopeful forecasts had turned out to be true. Just as a well-designed clinical trial disproved the notion that postmenopausal hormones could keep women heart-healthy, controlled clinical trials of vitamin E have found this supplement wanting, as well. The same is true of another antioxidant, vitamin C.
Too Much of a Good Thing
Recent studies have even suggested that at the high doses many people consume, vitamin E could be hazardous. In November 2004, the American Heart Association warned that while the small amounts of vitamin E found in multivitamins and foods were not harmful, taking 400 International Units a day or more could increase the risk of death. The highest recommended dietary allowance for vitamin E is 28.5 IU, for women who are breast-feeding.
No one knows whether other antioxidants, taken as supplements or as concentrates in gourmet beverages, will meet a similar fate, because they have not been rigorously studied. And given the length, cost and difficulty of conducting the needed studies, chances are that these other antioxidants will never be properly investigated. So you may never know whether spending a fortune on pomegranate juice or the like is worth it.
Some vitamin E enthusiasts object that the clinical studies used what they consider the wrong form of the vitamin, saying that each of the vitamin’s eight forms has its own biological activity. But the kind of vitamin E used in most studies, alpha-tocopherol, is the most active form in humans, according to the National Institutes of Health’s Office of Dietary Supplements.
Here, then, is what we now know about vitamin E from recent randomized, controlled clinical trials, the gold standard of research if the right questions were investigated.
Cardiovascular disease. An early hint of no benefit to the heart came from a 2001 University of Pennsylvania study of 30 healthy men, which found that at doses of 200 to 2,000 I.U.’s, vitamin E did not prevent oxidation of blood fats that can damage arteries. Four years later, the Heart Outcomes Prevention Evaluation trials, which looked at nearly 10,000 patients 55 and older with vascular disease or diabetes, found no heart benefit from taking 400 I.U.’s of vitamin E daily for an average of seven years. In fact, those taking the vitamin were more likely to develop heart failure, which prompted the heart association warning.
A few months later came a report on healthy women. The Women’s Health Study, of nearly 40,000 women 45 and older who were followed for an average of 10 years, found no overall benefit in taking 600 I.U.’s of vitamin E every other day for major cardiovascular events (heart attacks and stroke) or total mortality. There was, however, a 24 percent reduction in cardiovascular deaths.
A fresh report on men was released last November. In it, the Physicians’ Health Study, 14,641 men 50 and older were followed for up to eight years, it was found that 400 I.U.’s of vitamin E every other day had no effect on the incidence of major cardiovascular events, including cardiovascular deaths.
The bottom line of all these reports was that supplements of vitamin E could not be relied upon to protect against heart disease and stroke.
Cancer. The Heart Outcomes trials also looked at cancer and found no differences in cancer incidence or deaths during the seven-year follow-up that could be attributed to vitamin E.
Likewise, the Women’s Health Study found no significant effect of the vitamin on total cancer incidence or cancers of the breast, lung or colon, nor any effect on cancer deaths.
Still, hope lingered that vitamin E alone or in combination with the mineral selenium or vitamin C would protect men against prostate cancer. No such luck. In the Jan. 7 issue of The Journal of the American Medical Association, two major reports seemed to have offered the final word on this question.
The Select trial (an acronym for the Selenium and Vitamin E Cancer Prevention Trial) followed 35,533 men from 427 locations in the United States, Canada and Puerto Rico for more than five years. It found no benefit, but did find a “statistically nonsignificant increased risk of prostate cancer” in the group taking 400 I.U.’s a day of vitamin E. Selenium alone offered no benefit, and neither did selenium combined with vitamin E.
The second study, a continuation of the Physicians’ Health Study, found that among male doctors who took 400 I.U.’s of vitamin E every other day and 500 milligrams of vitamin C every day, there was no decreased risk of developing prostate cancer or cancer in general.
For lung cancer, a 2007 study financed by the National Cancer Institute found that smokers who took vitamin E supplements had a somewhat higher risk of developing the disease.
Other diseases. An independent review of studies by the Cochrane Collaboration published last year found no reliable evidence for the ability of vitamin E to prevent or treat Alzheimer’s disease or mild cognitive impairment, not even at doses of 2,000 I.U.’s a day.
And while vitamin E is part of complex formulations that have been found to slow the progression of macular degeneration, no one can say if the vitamin has played any role in the benefits seen with these products.
There are possible risks as well, since vitamin E diminishes the clotting tendency of blood and may result in ugly bruises from small bumps.
Simply put, there is no quick fix. The best chance for leading a long and healthy life comes not from any pill or potion but from pursuing a wholesome lifestyle. That means following a nutrient-filled but calorically moderate diet rich in vegetables, fruits and whole grains (many are good sources of vitamin E); not smoking; exercising regularly; maintaining a normal body weight; and driving and riding safely.
Here’s to your health.
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