C change

Do the vitamins in citrus fruits really prevent the common cold?

oranges 88 (photo credit: Courtesy)
oranges 88
(photo credit: Courtesy)
Vitamin C may be the most popular go-to remedy for the prevention and cure of the common cold. At the slightest sign of a sniffle, many of us immediately run to the medicine cabinet, and in a newfound display of earnest dedication, purposefully begin a regimen of serious vitamin C intake. Where did this association between vitamin C and cold prevention/treatment come from? Is it merely a myth, or does vitamin C truly contain cold-curing powers? Widespread popularity of vitamin C, or ascorbic acid, as a remedy for the common cold began in 1970 with the publication of scientist and Nobel Prize winner Linus Pauling's book, Vitamin C and the Common Cold. Pauling's book sought to draw conclusions about the relationship between vitamin C and the common cold from earlier scientific studies. While the daily recommendation for vitamin C is 75-90 milligrams per day for the average adult, Pauling claimed that a daily intake of about 1,000 milligrams of vitamin C or more per day (roughly 13 times the daily recommendation) would reduce cold occurrence by 45 percent. Pauling reportedly took at least 12,000 mg. of vitamin C daily. In recent years, the veracity of this claim has been tested numerous times through repeated scientific trials. In general, to test the efficacy of vitamin C in the prevention and cure of the common cold, groups given high doses of vitamin C are compared to similar groups given a placebo, and conclusions are drawn from the ensuing results. Dozens of studies have been conducted to help ascertain whether or not vitamin C harbors any real therapeutic effects in combating the common cold, and according to the overwhelming evidence, in normal populations, vitamin C neither helps reduce the risk of the common cold, nor does it significantly mitigate the severity of its symptoms. Exceptions were seen, however, in certain subjects exposed to extreme environments or conditions. Scientists from Australia and Finland recently reviewed the best quality studies published over the last 50 years that examined the relationship between vitamin C and the common cold. After analyzing 30 studies conducted among the general population using high doses of vitamin C against a placebo, they concluded that, "the failure of vitamin C supplementation to reduce the incidence of colds in the normal population indicates that routine mega-dose prophylaxis [ie. taking high doses of vitamin C to prevent the onset of a cold] is not rationally justified for community use." Nevertheless, that is not to say that vitamin C supplements should be thrown out the window. Although vitamin C may not do much to treat or prevent the common cold, it certainly harbors other health benefits. Aside from its antioxidant properties, vitamin C aids in the absorption of iron, and is vital for the formation of collagen in our bodies. Collagen, the main protein of our connective tissue, is the chief component of cartilage, ligaments, tendons, bone and skin and is essential for the support of most of our tissues and cells. However, taking mega-doses of the vitamin via supplementation is unadvisable, and is by no means required in order to enjoy its health benefits. To get the vitamin C that one needs, one need not look any further than the refrigerator. Vitamin C is found in a variety of fruits and vegetables, particularly in citrus fruits such as oranges and grapefruits. Hopefully the upcoming winter won't bring with it a bout of colds, but if it does, you may want to think twice before dutifully popping those vitamin C pills. It certainly can't hurt to eat an extra orange or two the next time you feel a cold coming on, but, according to the latest research, don't expect it to save you from missing a day of work. Shira Gluck earned her MA in nutrition and education from Teachers College, Columbia University. She divides her time between nutrition research, education and private counseling. ssf2111@columbia.edu.