What about doses beyond the 60 mg RDA? "Any benefit that might be derived from such use of ascorbic acid," they concluded, "seems small when weighed against the expense and the risks of megadosage treatment." They did note that vitamin C could also be used "as an antioxidant to protect natural flavor and color of many foods." No mention was made of protecting humans from oxidative damage, however. That was the medical gospel in 1990. In fact, that had been the medical gospel since vitamin C was discovered more than 50 years earlier, and for many physicians, nutritionists. and dietitians, it still is.
OPTIMAL, NOT MINIMAL
For many others, though, a new day has dawned, heralding a "second wave" of vitamin use, where the goal is optimal, rather than minimal levels. Consider another article entitled "Vitamin C Intake and Mortality Among a Sample of the United States Population," by James E. Enstrom, MD, and his colleagues at the UCLA School of Public Health, and published this past spring in the journal Epidemiology.2 Drawing his findings from a carefully controlled, 10year-long survey of more than 11,000 adults, Enstrom reported that men who took vitamin C supplements in variable doses above the RDA lived an average of 6 years longer than those who got all their vitamin C with a knife and fork. Much of the benefit seemed to derive from a reduction in deaths from cardiovascular diseases. They also found that people who took vitamin C supplements and also got a reasonable amount of vitamin C from food did better than those who ate well but did not take supplements.
When Enstrom then went back and reexamined some old studies of vitamin C and longevity, one more than 40 years old, he found a similar effect-a 50% reduction in total death rate in people who took more than 50 mg per day of vitamin C in one study, and in another a 60% reduction in deaths in people taking more than 750 mg per day. Enstrom speculated that it was the antioxidant effects of high levels of vitamin C (as well as vitamins E and A) against free radicals that helped reduce the risk of atherosclerosis in these people. He also noted that his current finding of increased longevity in vitamin C users was consistent with trends during the last 20 years "of large increases in the consumption of vitamin C and large declines in age-adjusted death rates (total, cardiovascular disease, and stomach cancer) in the general population that are only partially explained by established risk factors."
MORE THAN JUST CHOLESTEROL
Moreover, Enstrom pointed out, the relation between increased vitamin C intake and reduced mortality was "stronger and more consistent in this population than the relation of total mortality to serum cholesterol and dietary fat intake, two variables on which strong public health guidelines have been issued over the years." Representing, as these articles do, widely differing eras in medical thinking and understanding, many of the conclusions they draw regarding the value and use of vitamin C (ascorbic acid) are quite different. This comes as no surprise: Times change. Doctors don't practice bloodletting anymore either. What is surprising is the span of time the two articles represent-just 2 years, from 1990 to 1992. While much information about vitamin C has been around for decades-Linus Pauling published "Vitamin C And The Common Cold" more than 22 years ago-a critical mass has clearly formed in recent years.
Even as the FDA pursues an active retreat from scientific reality by reducing the average daily requirement, many in the medical and nutritional establishment, from the U.S. Department of Agriculture to the National Cancer Institute (NCI) to some of the FDA's own researchers, seem to be taking the megadose route. In December 1991, the National Institutes of Health (NIH) published the proceedings of a 3-day conference-"Ascorbic Acid: Biologic Functions and Relation to Cancer"-as a special supplement to the American Journal of Clinical Nutrition. Sponsored by the NCI and the National Institute of Diabetes and Digestive and Kidney Diseases, the conference brought together dozens of the world's leading researchers on vitamin C, who presented evidence supporting the role of vitamin C supplements in preventing cardiovascular disease, cancer, and ocular cataracts. As research scientist Durk Pearson says "It's a lot harder for skeptics to shrug off 200 supporting studies than 20 studies."
One benefit of vitamin C has been known in some form since the days of the Crusades, when northern European populations were forced to subsist on diets lacking in fresh fruits and vegetables for many months every year. Too little vitamin C in their diet deprived their body of one of the key ingredients for making collagen, which gives bone, teeth, and other connective tissue much of their strength. The resulting disease, known as scurvy, was often fatal and was always a major concern during long, cold winters and on extended sea voyages. The introduction of the vitamin C-rich potato to northern Europe during the 17th century was an early milestone in the life-extension movement. Canadian Indians taught Cartier (the explorer, not the jeweler) how to cure scurvy in his crew by drinking a tea made from boiling spruce leaves. Later, lemon juice was found to work as well.
ROOTS OF SKEPTICISM
It took more than 200 years before the first "clinical" trial of diet and scurvy was performed. In 1747, a British naval physician named Lind gave men with scurvy either cider, vitriol, vinegar, sea water, oranges and lemons, or garlic and mustard. The men who received the citrus fruits recovered. It was nearly another 200 years before the next significant event: the identification of ascorbic acid as the active anti-scurvy substance by Szent-Gyorgyi in 1932.
One root of the traditional skepticism about the benefits of vitamin C and other nutrient supplements seems to lie in the way the nutrients were discovered-by their absence. Many of the great medical breakthroughs of the early 20th century involved the identification of one or another nutrient deficiency, e.g., beri-beri, pellagra, and rickets. But somehow, the idea that the only function of vitamins was to prevent deficiency diseases took hold in the medical and nutritional mindset and has only recently been widely questioned.
Even as the FDA pursues an active retreat from scientific reality by reducing the average daily requirement, the USDA, the NCI, and some of the FDA's own scientists, are taking the megadose route. In an editorial accompanying Enstrom's article in Epidemiology, Dr. Gladys Block, of the University of California, Berkeley, School of Public Health, nails the lid shut on the deficiency model of nutritional need. "It is quite clear," she observes, "that free radicals and oxidative damage play an important role in many diseases, and thus it is not unreasonable that antioxidants of various sorts (vitamin C, vitamin E, carotenoids, and others) have a nonspecific, general role in preventing or repairing various types of damage...The results of Enstrom et. al. indicate that increased attention should be given not only to dietary sources of these nutrients, but also to the possible benefits of vitamin supplements."
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