Vitamin C May Reduce Chronic Inflammation

BERKELEY, Calif.--<$>Vitamin C may reduce levels of C-reactive protein (CRP), a marker of chronic inflammation, thereby decreasing the risk of many diseases including atherosclerosis, according to a newly published study in the Journal of the American College of Nutrition (23, 2:141-7, 2004) (www.jacn.org).

One-hundred sixty subjects who either smoked or were exposed to second-hand smoke were involved in the randomized, double blind, placebo-controlled study. Subjects received either 515 mg/d of vitamin C, an antioxidant mixture (containing 515 mg/d of vitamin C, 371 mg/d of alpha-tocopherol, 171 mg/d of gamma-tocopherol, 252 mg/d of mixed tocotrienols and 95 mg/d of alpha-lipoic acid) or placebo for two months. Plasma CRP levels were measured before and after the two-month supplement period.

Researchers found CRP levels decreased 24 percent in subjects receiving vitamin C supplements compared to subjects receiving placebo. CRP levels decreased 4.7 percent in subjects receiving the antioxidant mixture compared to the placebo group--an insignificant change, according to researchers. Those taking placebo experienced an increase of 4.3 percent in CRP levels.

C-reactive protein is a marker of inflammation and there is a growing body of evidence that chronic inflammation is linked to an increased risk of heart disease, diabetes and even Alzheimers disease, said Gladys Block, Ph.D., lead author of the study and professor of epidemiology and public health nutrition at UC Berkeley. If our finding of vitamin Cs ability to lower CRP is confirmed through other trials, vitamin C could become an important public health intervention.

Block noted that in other studies, higher doses of vitamin E produced lower CRP levels among Type II diabetics and health individuals. We were surprised to find no statistical change in CRP levels among people taking the antioxidant mixture, while whose taking the vitamin C supplement saw a significant 24-percent drop, Block said. Its possible that there is some interaction among the antioxidants that rendered the mixture less effective in reducing CRP levels, but thats not clear at this time. This underscores the need to conduct further tests to confirm our findings.

The study was supported by the University of California Tobacco-Related Disease Research Program and by the National Cancer Institute (NCI).