Most ads for sports supplements feature obvious incentives: washboard abs, swooning women, and the promise of acrobatic sex. One not-so-obvious ploy is the "consumer health alert" used recently to promote a muscle-boosting powder. The ad boasts that the ingredients "are so powerful that the FDA has instituted a research panel to ban the sale of it over the counter. Please act immediately before this product is banned."
In the past decade, performance-enhancing supplements have grown into a $1.6 billion industry, but even the experts don't know if the companies are selling risk or reward. "Twenty years ago, if you said dietary supplements, that meant vitamins, minerals, and protein powders," says Ann Grandjean, executive director of the Center for Human Nutrition in Omaha, Nebraska. She studies supplement use in Olympic athletes. "Today there are so many products that qualify as supplements, when people ask me what I think about them, I have to say, 'Can you be a little more specific?'"
The substances deemed "supplements" under a 1994 federal law include everything from the electrolytes in Gatorade to stimulants and hormones that have been linked with serious side effects and even, critics charge, with death. Known as the Dietary Supplement Health and Education Act, the law was crafted to help protect access to herbal remedies and New Age nostrums. The act states that supplements don't need to undergo the rigorous tests of safety and efficacy that drugs do. It also allows the unrestricted sale of some compounds not ordinarily found in the diet—as long as they come from so-called natural sources. Certain hormones, for example, can be considered supplements if they're derived from animal extracts rather than synthesized in the lab. "The act said you're going to regulate a precursor hormone with the same law that you regulate vitamin E," gripes Grandjean.
That means thyroid-stimulating hormones can be sold as fat-burning supplements, and bodybuilders can swallow testosterone analogues in the hopes of building lean muscle. Athletes look for a boost in their game. Mark McGwire of the St. Louis Cardinals admitted that a testosterone precursor, androstenedione, may have helped him hit 70 home runs in the 1998 season. In one of the few controlled studies of androstenedione, recommended doses had no effect on muscle size and strength. "But nobody really knows how much people are taking," says study leader Doug King of Iowa State University. "My guess is it's a lot more." Even at modest doses, King says, androstenedione changes cholesterol levels enough to increase the risk of heart disease by 10 to 15 percent. At high doses, it may disrupt pituitary function, causing atrophy of the testicles. Testosterone precursors could also stunt the development of bones and muscles in teenagers, says John Cardellina of the Council for Responsible Nutrition in Washington, D.C. "This group of products has no business being used by people under 18," he says.
Organizations such as the National Football League and the International Olympic Committee have worked to regulate supplement use among elite athletes; androstenedione, for example, has already been blacklisted by both. But high school athletes, exempt from urine tests and sanctions, can use and abuse it and other supplements at will. In a recent survey by the National Collegiate Athletic Association, more than half the college athletes who reported taking the stimulant ephedrine say they first tried it in high school.
And ephedrine is one of the biggest problems in the pantry. It's the active principle in the herb ephedra, or ma huang, a staple of Chinese medicine that has long been used to suppress appetite, curb fatigue, and clear the sinuses. Today ephedra derivatives are the main ingredients in most over-the-counter decongestants, and they're the top-selling botanicals for losing weight. Some athletes use ephedrine-laced supplements for a pick-me-up before practice.
But like any stimulant, ephedrine revs up the body. Typical side effects include racing heart, shortness of breath, dizziness, and palpitations. It's also been blamed for high blood pressure, heart attacks, seizures, and stroke. The FDA has received more than 1,400 reports of adverse reactions to ephedrine, including dozens of deaths, and has proposed limiting its sale. Ephedrine use is already prohibited by the NFL, the NCAA, and the IOC. But many athletes dismiss the dangers. Most get their fix from decongestants rather than sports supplements anyway, says Grandjean, so restricting supplement sales isn't likely to curb abuse.
To make matters more complicated, it seems that at least one performance supplement might actually work safely and well. That banner goes to creatine, a critical component of the main energy-producing pathway in cells. Unlike hormone precursors or ephedra, creatine is part of a normal diet, most abundant in beef, pork, and fish. But there's evidence that supplement use can boost muscle stores of creatine and that those increases can improve performance in short-duration, high-intensity sports like sprinting and weight lifting. "It's one of the few supplements that has a substantial body of scientific literature to support its efficacy," says Jeff Volek, a kinesiologist at the University of Connecticut at Storrs and a competitive power lifter who has used creatine himself. He dismisses charges that the compound may cause muscle cramps and dehydration: "It's hype. There's no scientific evidence that there's any link with adverse effects."
"Creatine is basically as harmless as you can get when it comes to a performance-enhancing dietary supplement," says Grandjean. Athletes are voting with their wallets: Creatine sales increased sixfold between 1995 and 1998. When Grandjean and her colleagues tried to track its use on the gridiron, she says, "we couldn't find any football players who didn't take creatine."
Creatine might also have a future beyond the gym. Volek thinks it could help the elderly retain muscle mass or supply vegetarians with an energy lift they don't get from their diets. Researchers are exploring its potential as a treatment for muscular dystrophy and Parkinson's disease, where it could help compensate for neuromuscular damage.
But Volek cautions that claims for creatine's performance-enhancing effects may be exaggerated. "It's not going to turn an average athlete into an all-American overnight," he says. He'd like to see more studies of women and adolescents, to make sure it's safe in those groups. There aren't any long-term studies of chronic use, and there are many sports for which its efficacy hasn't yet been demonstrated. But that could be said of all sports supplements. So what's a weekend warrior to do?
"My advice is to read and heed," says Cardellina, who maintains that most supplements are labeled responsibly. "If it's a multi-ingredient product, read down the list, see what's in there, and read the warnings. Don't take more than it says, and don't take it if you're in a contraindicated group."
Finally, resist the urge to rush out and buy a supplement before it's banned by the FDA.
The FDA offers information about supplements at www.cfsan.fda.gov/~dms/supplmnt.html.