Friday, November 5, 2010

Another Vitamin E Meta-Analysis on Vitamin E and Stroke Risk

The British Medical Journal just published another Vitamin E study suggesting that supplemental Vitamin E increases the risk for hemorrhagic (aneurism, or bleeding in the brain) stroke. Vitamin E did not increase the risk of ischemic (thrombosis, or blood clot) stroke.  This will, no doubt, alarm the public and those docs who only read headlines and don't bother to read the entire study before recommending that their patients stop taking supplemental vitamin E.

Here are a few reasons to stay positive about vitamin E supplementation.
  1. The majority of this meta analysis data was derived from studies involving diseases on high risk patients, so the results probably are not all that relevant to the general population. 
  2. This analysis only looked at studies involving supplemental vitamin E alone. We know that antioxidants (and all nutrients) don't function in isolation but as part of complex networks, so the idea that a single nutrient will have potent effects is probably misplaced to begin with.
  3. The study did not identify the percentage of participants who were supplementing with synthetic (dl) alpha tocopherol vitamin E vs. natural d-alpha tocopherol vitamin E.  
  4. Neither did the study identify the lucky subjects who were supplementing with a biochemically balanced mixture of alpha, beta, gamma and delta tocopherols and tocotrienols, which make up a  natural vitamin E molecule.
FYI:  The meta-analysis study authors estimated that for every 1000 high risk patients exposed to supplemental vitamin E they would predict 0.8% more hemorrhagic strokes and 2.1% fewer ischemic strokes.  So the benefits may actually outweigh the risks, when it come to stroke.