“Dietary Supplement Sales Soar With No Scientific Proof”
There is a mountain of failed studies on the benefits of dietary supplements, but people continue to buy them by the bucket loads and gobble them down. Americans spend about $40 billion annually, as global sales reach $133 billion. But why? In 1996, the Physicians’ Health Study randomly gave men beta-carotene or placebo for 12 years and showed no difference in cardiovascular disease (CVD), or for that matter in malignant neoplasms or overall mortality. In fact, other evidence showed that beta-carotene might actually increase the risk for lung cancer in smokers. The Women’s Health Study of almost 40,000 women older than 45 years compared beta-carotene with placebo and also found no benefit in terms of stroke, myocardial infarction, or cardiovascular death. The evidence for vitamin C and vitamin E has been equally disappointing, despite great hope that as antioxidants, they would have some benefit. The second Physicians’ Health Study compared vitamin E, vitamin C, or both against placebo in over 14,500 men and found no reduction in stroke, myocardial infarction, or cardiovascular mortality. The Women’s Antioxidant Cardiovascular Study tested beta-carotene, vitamin C, and vitamin E in 8,171 women over 9 years of follow-up and also found no benefit. The ability of folic acid to lower homocysteine levels initially held promise, but subsequent reviews showed it was not associated with a reduction in CVD.
