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Monday, July 16, 2018

Too Much of a Good Thing

Extra Vitamin E may cause you harm; instead of supplements,get it from food

Written by New York Times | Published: March 28, 2009 10:53:49 pm

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,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 the by-products of metabolism and exposure to cell-damaging agents like sunlight,radiation and chemotherapy.

Ever hopeful for a magic elixir,millions began dosing themselves with amounts of Vitamin E dozens of times greater than the recommended intake.

If only all those hopeful forecasts had turned out to be true. Controlled clinical trials of Vitamin E have found this supplement wanting. The same is true of another antioxidant,Vitamin C.

Recent studies have even suggested that the high doses people consume could be hazardous. In November 2004,the American Heart Association warned that while the small amounts of Vitamin E found in multivitamins and foods are not harmful,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 – meant for lactating women.

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 randomised,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 IUs,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 IUs 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 IUs of Vitamin E every other day for major cardiovascular events or total mortality. There was,however,a 24 per cent 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 IUs of Vitamin E every other day had no effect on the incidence of major cardiovascular events,including cardiovascular deaths.

The bottomline of all these reports was that supplements of Vitamin E could not be relied on 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 will protect men against prostate cancer. No such luck. In the January 7 issue of The Journal of the American Medical Association,two reports seemed to have offered the final word on this question. The Select trial that followed 35,533 men for over five years found no benefit. Worse,it found a “statistically nonsignificant increased risk of prostate cancer” in the group taking 400 IU 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 IU 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 US 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 evidence of the ability of Vitamin E to prevent or treat Alzheimer’s Disease or mild cognitive impairment.

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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