Sunday, December 19, 2010

Vitamin E and Stroke Risk

A recent article in the British Medical Journal, a news release from the publisher, and news stories published around the world was nothing less than misleading and alarming. The article, based on an analysis of nine previously published studies, reported that vitamin E supplements increased the risk of stroke.

Wait a minute! The study and all the negative publicity were deeply flawed.

First, none of the individual studies had found an increased risk of stroke. Second, the dosages varied from 300 IU to 800 IU of vitamin E daily, some using natural and others using synthetic vitamin E. The studies ranged from about a year and one-half to 10 years, the subjects varied from middle-age to seniors, and some were healthy while others were at high risk of cardiovascular disease (and whom were likely to be taking several medications). With this disparate data, the researchers concluded that one additional person in every 1,250 taking vitamin E would suffer a hemorrhagic (bleeding) stroke, whereas about 2.6 additional people in 1,250 would be less likely to suffer an ischemic (clotting) stroke.

You would think that the significantly greater reduction in ischemic stroke would be the subject of headlines. But it wasn’t. The researchers downplayed the benefits, and headlines warned that vitamin E increased the risk of stroke.

Here’s what else you need to know: you are far more likely to suffer an ischemic stroke. That’s because 90 percent of all strokes are related to blood clots. You are far less likely to suffer a hemorrhagic stroke; they account for only 10 percent of all strokes.
Even though this study was poorly designed, it showed that vitamin E supplements significantly reduced the risk of the most common type of stroke, whereas it slightly increased the risk of the least common stroke. You don’t have to be a rocket scientist – or a statistician – to figure out that the benefits:risk ratio of vitamin E supplements is strongly in your favor.