From The June 2001 Issue of Nutrition Science News

Vitamin C Lengthens Lifespan

Although vitamin C has long been considered the premier antioxidant, studies linking the vitamin to increased survival rates have been inconclusive. However, a major study conducted by researchers at Cambridge University School of Clinical Medicine in the U.K. and published in Lancet offers evidence that vitamin C saves lives.

This analysis, part of the nine-country European Prospective Investigation into Cancer and Nutrition, was conducted on 19,496 men and women, ages 45 to 79, in Norfolk, U.K., between 1994 and 1997. The participants described their supplements intake, had their plasma tested for ascorbic acid, and kept a detailed five-day diet diary. They were placed in five groups according to their serum ascorbic acid levels. Because women naturally have higher serum ascorbic acid levels, men and women were tracked separately.

Prior to December 1999, the researchers observed how many people died of cardiovascular disease, ischemic heart disease, cancer, and all causes in each of the serum ascorbic acid quintiles. In every case (except for women at risk of cancer), death rates were significantly lower among those with higher serum ascorbic acid levels. People with the highest ascorbic acid levels had half the risk of dying from all causes combined. The chances of dying from cardiovascular disease were reduced by 71 percent in men and 59 percent in women in the group with the highest ascorbic acid levels compared with the lowest. The results were virtually the same when smokers and supplements users were eliminated from the analysis (one-third of the men and half the women took nutritional supplements).

The researchers suggest that the true protective power of vitamin C is stronger than they reported because of individual variables. There was a consistent dose-response relationship across the distribution of ascorbic acid intake. A change from the 30th to the 70th percentile in intake was associated with a 30 percent reduction in mortality. Thus, a practical shift within the normal population could substantially reduce death rates.

—Lancet, 2001 Mar 3;357:657-63.