Journal commentary suggests flawed studies intentionally obscured benefits of vitamin therapy in preventing strokes

Friday, January 06, 2012 by: Jonathan Benson, staff writer
Tags: vitamins, strokes, medical journal

(NaturalNews) Prior to the release of several studies that claim the therapy is ineffective, taking high doses of B vitamins was considered an effective regimen for lowering homocysteine levels, and thus helping to prevent strokes and cardiovascular disease. But a new commentary published in the Journal of the American Medical Association (JAMA) suggests that these negative studies are flawed, and that B vitamin therapy is still an effective heart protection therapy.

Dr. David Spence from the University of Western Ontario and Dr. Meir Stampfer from the Harvard School of Public Health together published a review in JAMA that explains why B vitamins can still help to lower homocysteine levels, which is believed to also lower the risk of stroke and heart attack. Despite several recent studies, including one by Dr. Spence, that seem to show that B vitamin therapy does not affect levels of this amino acid, the duo now says these studies ultimately failed to consider other important factors that affect the outcome.

"It is now clear that the large trials showing no benefit of vitamin therapy obscured the benefit of vitamin therapy because they lumped together patients with renal failure and those with good renal function," said Dr. Spence. "The vitamins are harmful in renal failure, and beneficial in patients with good renal function, and they cancel each other out."

Renal function, of course, refers to kidney function. And those with kidney failure or kidney disease may not derive much benefit from vitamin therapy because their bodies are unable to process high doses of vitamins. Particularly when synthetic vitamins are used, those with poor renal function may not be able to filter out the excess vitamins, which can cause toxicity.

Another area where Dr. Spence says certain studies have missed the boat on vitamin therapy is dosages. While arrogantly claiming that "homocysteine is dead," many researchers failed to use high enough doses of vitamin B12, for instance, to derive any tangible benefit in patients. Effective vitamin therapies involve taking doses far higher than what the federal government recommends on a daily basis.

A 1998 study out of the University of Maryland, for instance, found that patients taking 100 milligrams of vitamin B6, one milligram of vitamin B12, and five milligrams of folate every day saw a significant lowering of homocysteine levels after three months. These dosages, however, are up to 100 times higher than the recommended dietary allowance (RDA), and studies that claim vitamin therapy is ineffective typically use far lower doses (http://www.sciencedaily.com/releases/1998/02/980211072308.htm).

Sources for this article include:

http://www.eurekalert.org/pub_releases/2011-12/uowo-jcc122111.php