Saturday, November 29, 2008

A special case: The continuing saga of vitamin C


In 1970, chemist Linus Pauling published Vitamin C and the Common Cold, a small book (just about 100 pages) made weightier by the fact that Pauling had not one, but two Nobel prizes on his shelf — one for chemistry and one for peace. Ever since, people have been fighting over Pauling’s message that very large doses of vitamin C — called gram doses because they provide more than 1,000 milligrams (1 gram) — prevent or cure the common cold or his later (unfounded) claim that these doses may also cure advanced cancer.
Over the past decade, the argument has switched to vitamin C’s reputed ability to protect heart health. For example, an April 2004 report in the Journal of the American College of Nutrition said vitamin C could lower blood levels of CRP, an inflammation-related protein that increases the risk of heart disease. University of California, Berkeley, researchers gave 160 healthy adult volunteers either 500 milligrams vitamin C or a mixture of antioxidant nutrients or a look-alike pill with no nutrients once a day for two months. In the end, the folks who got the vitamin C experienced a 24 percent drop in CRP blood levels versus a statistically insignificant 4.7 percent for the cocktail and no change at all for those on the placebo. Not surprisingly, UC epidemiologists thought vitamin C may become an important aid to heart health.
Unless, that is, you’re taking medicines to knock down your “bad” cholesterol and boost the “good” kind. As the American Heart Association (AHA) Council on Nutrition Physical Activity and Metabolism points out, when 20 volunteers in an HDL-Atherosclerosis Treatment Study were given vitamin C supplements along with their anti-cholesterol meds, they ended up with lowerthan-expected levels of heart healthy high density lipoproteins (HDLs). In another small study, women taking antioxidant vitamins along with post-menopausal estrogens were more likely than those taking look-alike pills to die from their heart disease.
Oh, well. Nothing’s perfect.

No comments: