The Truth About Supplements

Multivitamins
Everybody needs vitamins for good health. A balanced diet should give you all the vitamins you need, and taking extra won’t necessarily help. Sure, a multivitamin with no more than the recommended daily amount of nutrients probably won’t hurt you. But studies of multivitamin intake among well-fed Western populations provide little evidence supporting the use of a daily multi. The most prominent, published last fall in the Journal of the American Medical Association, showed no significant difference in cancer-mortality rates between those who take a multi and those who don’t (though users had a slightly lower risk of cancer incidence). And studies of cardiovascular-disease risk show no difference at all.

Antioxidant Supplements
The conventional wisdom about antioxidants is that when we burn energy, free radicals (oxygen atoms that are missing some electrons) go bouncing around inside our cells, causing havoc. Antioxidants scoop them up. But your body has an antioxidant system of its own. It’s one of the ways it responds to exercise—a kind of what-doesn’t-kill-me-makes-me-stronger reaction. So if you’re eating a diet rich in fruits and veggies, you probably don’t need high doses of supplemental antioxidants like vitamins C, E, or beta carotene (which the body turns into vitamin A). In a landmark study by the National Cancer Institute and a Finnish partner, smokers who took lots of extra beta carotene died at a higher rate than smokers who didn’t. And in 2011, the NCI’s large Selenium and Vitamin E Cancer Prevention Trial (SELECT) found that patients taking vita-min E alone were 17 percent more likely to develop prostate cancer than those taking a placebo. Scientists call this the antioxidant paradox, and some speculate that over-dosing on supplemental antioxidants can unbalance a delicate system.

Fish Oil
Fish such as salmon and sardines are rich in omega-3 fatty acids, which can help your cardio system and brain. So taking fish-oil pills would seem to be good for you, too. But this summer, Ohio State University researchers using data from the SELECT study and another NCI study, the Prostate Cancer Prevention Trial, found that men with high concentrations of the omega-3 fatty acid DHA in their blood had a significantly greater risk of prostate cancer. Last year, the Journal of the American Medical Association ran a major meta-analysis that concluded that omega-3 supplementation was not associated with a lower risk of “mortality, cardiac death, sudden death, myocardial infarction, or stroke.”

Glucosamine
Glucosamine is a constituent of cartilage, so it seems logical that taking it in pill form could help prevent joint pain and injury. But there’s no real proof that it does. In 2010, one portion of a huge controlled trial called GAIT, conducted by University of Utah researchers, showed that a glucosamine supplement wasn’t significantly better than a placebo for osteoarthritis of the knee. Doctors at the Mayo Clinic believe that it may help but point out that the variety found to be effective in clinical trials is a European one, glucosamine sulfate. Some argue that it’s the sulfate, a salt, that could help arthritic knee pain, so if you decide to take glucosamine, look for glucosamine sulfate. 

Human Growth Hormone
Contrary to the HGH-doping panic in pro sports and the sales pitches from anti-aging doctors, there’s no evidence that HGH increases muscle strength. Apparent gains in lean muscle mass seem to come because users retain water. Taking extra HGH may improve healing of ligament and cartilage injuries, but the jury’s still out. And it can cause side effects like joint and muscle pain. But mainly, HGH is a little scary because nobody knows what extra doses of it will do in the long term. It sits at the top of an extremely complex endocrine pyramid, one you probably don’t want to screw around with, especially when it’ll cost you a small fortune.