Supplements Gaining Muscle

After bashing a home run in his first game of the season, all eyes are once again on slugger Mark McGwire.

Now, if you’re wondering what that has to do with health, the answer is: lots.

After breaking baseball’s home-run record last season, McGwire became the reluctant poster boy for the booming sports supplements business. If he goes on another home-run tear this year, just watch the sales of androstenedione and creatine--supplements he says he takes--continue to rise.

Of course, McGwire isn’t the sole reason for the wild popularity of pills, powders, energy bars and drinks that make up the field of sports supplements--a business that has grown to an estimated $1.27 billion a year, according to the Nutrition Business Journal. Millions of Americans are interested in methods that will give them more effective workouts, regardless of whether they are competitive athletes.

Helping to spark that interest is a handful of research studies that show supplements might be effective in treating certain diseases.

“Three or four years ago, you’d have to go to specialty stores to find sports supplements. Now, they’re everywhere,” says Edmund Burke, director of exercise science at the University of Colorado in Boulder.

“They’re no longer being used just by the strength athlete or bodybuilder. It’s the aerobic and endurance athlete and the aging population that wants to keep exercising, that is the next big wave in sports supplements.” SportPharma, a Concord, Calif., company that makes the ProMax energy bar, reports that 80% of its product sales are through South Pasadena-based Trader Joe’s, a chain of specialty grocery stores popular with health-conscious baby boomers.

“Weekend athletes are now using products that we’ve shipped to the Olympic Village for years,” says SportPharma President Mike Walls, who adds that the industry has grown 40% to 50% annually in recent years.

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Sports supplements can be nutrition products, such as vitamins, minerals and protein, as well as natural substances like herbs, amino acids and hormones.

According to the American College of Sports Medicine, the majority of elite male athletes and half of all elite female athletes consume one or more supplements. The college estimates that more than half of all male high school athletes and about one-third of female high school athletes take supplements to enhance performance.

But as more sports supplements appear on grocery store shelves, to be purchased by everyone from your 12-year-old son to your 80-year-old grandmother, some sports medicine experts are questioning how healthy this “health trend” actually is.

Much of the concern centers on the fact that, like other dietary supplements, sports supplements are largely unregulated. The federal government does not require manufacturers to prove that their products are either safe or effective before bringing them to market. And, under federal law, manufacturers can make fairly broad advertising claims about what their products do--short of making an actual health claim.

For instance, a glossy two-page advertisement in a fitness magazine boasts that a combination of creatine and a substance called HMB can lead to “huge muscle gains” and “faster recovery” after physical workouts. And an ad for androstenedione proclaims: “The supplement helped boost testosterone levels in test subjects a phenomenal 98%!”

The situation has many sports medicine experts crying foul. They say there is very little scientific data to support the enthusiasm around sports supplements. And, even more important, there is scant safety information about many of the most popular products.

“There is an absolute paucity of scientific literature on these supplements,” says Dr. Gary I. Wadler, an associate professor of medicine at New York University School of Medicine. “The field is built on narcissism, not on science.”

Several factors have probably led to Americans embracing sports supplements, says Peter J. Ambrose, an associate clinical professor of pharmacy at UC San Francisco, and a drug-testing crew chief for the National Collegiate Athletic Assn.

“If you’re an athlete, and a supplement can potentially help you run faster by a fraction of a second, and it means the difference between silver and gold and being a national hero, athletes will try it,” he says. “There have been some very popular and successful athletes who have acknowledged use of these supplements. People hear that and are willing to give [supplements] a try. And, because they are sold in the United States, people believe they must be safe. That’s a fallacy.”

Ads on the Internet and in fitness and bodybuilding magazines give the impression that there is ample research to support the claims of effectiveness, Wadler adds. While there is some legitimate, independent research on a few popular supplements, there is also less-reliable research, such as that done by manufacturers on their own products.

“For most of these products, the claims are very bold, very general and, many times, outrageous,” says Ambrose. “They are notorious for being marketed with deceptive or misleading claims. Inappropriate or invalid research is often cited to promote the products.”

SportPharma’s Walls agrees that much more research is needed in the field.

“Consumers need to ask for documentation that something works, preferably from a third party,” such as an independent lab or university that has tested the supplement, says Walls. “There are companies that are doing research and making sure their products work before bringing them to the marketplace. Sports nutrition has gotten out of the snake pit and is becoming a science of its own.”

However, many of the top-selling sports supplements have not been verified with independent, scientific testing. For example:

Creatine

This is the blockbuster sports supplement that is touted to boost strength and power in short-duration exercise. A fair number of studies have supported that claim, according to the American College of Sports Medicine. And recent medical studies showed the substance can help people with muscular dystrophy and, perhaps, amyotrophic lateral sclerosis by helping store more energy in muscles.

“There is a very extensive body of good literature on it,” says Wadler. “But there is no evidence that it works for high-intensity exercise, and we have no long-term studies about what could happen to someone who uses it long-term.”

Most of the studies on creatine are on college-age males, and there is little data to show if the substance even works in women or older people. The American College of Sports Medicine advises against the use of creatine, especially among teenagers.

Indeed, says Ambrose, the problem with even legitimate studies of sports supplements is that it would take a massive number of large studies to determine, specifically, who could benefit. “We can do small studies and look at a specific sport. But then we have to ask: Which event? Is it going to help in the sprint, the marathon, the shotput? These kinds of studies require a fair amount of time and scientific validity.”

Testing supplements for their effectiveness becomes even more complex when manufacturers mix several substances in one product. For example, the hottest trend with creatine is to combine it with such substances as citrate and pyruvate, supposedly to enhance its benefits. And, says Burke: “The evidence isn’t even close to being presented to show whether these [combinations] are effective.”

Chromium picolinate

Some studies have suggested this substance helps maintain glucose levels in order to build lean muscle mass. A study that appeared in April in the journal Diabetic Medicine found that chromium improved glucose control in a small number of people with steroid-induced diabetes. However, a study reported in February by the American College of Sports Medicine found that chromium had no effect in reducing body fat, increasing lean body mass or improving performance in athletes.

Antioxidants

Supplement manufacturers say that vitamins C, E and beta carotene are useful in reducing skeletal muscle damage and enhancing the immune system. There is only preliminary evidence to suggest this, says the American College of Sports Medicine in a position statement on supplements. The organization maintains that vitamin and mineral supplements, in general, are of no use unless an athlete has “overt nutritional deficiencies.”

The college has also warned that indiscriminate use of vitamins and minerals can cause such side effects as decreased blood coagulation time, gastrointestinal disturbances and iron overload. The academy reported that three iron-overload-induced cardiac deaths among athletes may have been precipitated by megadoses of vitamin C. People who are genetically predisposed to iron-overload are at greater risk from vitamin C megadoses.

Androstenedione

The supplement made popular by Mark McGwire has received little scientific scrutiny. A group of Harvard researchers expects to release results of a study of the supplement later this year. But even if it is effective, Wadler says, safety questions will remain. Androstenedione is a so-called hormone precursor that increases levels of the hormone testosterone in the blood, thereby increasing muscle mass, strength and power.

“Steroids can have side effects that aren’t seen for months, years or decades,” Wadler says. So dangerous is testosterone, he says, a special prescription is necessary to obtain it for medical use. But under the passage of the 1994 Dietary Supplement Health Education Act, substances that create testosterone in the body are not classified as drugs and can be sold over the counter--a situation Wadler calls “ludicrous.”

Wadler notes that androstenedione is converted in the body to a controlled substance. Yet, because of the 1994 law, no prescription is required to obtain it.

“That makes no sense,” he says.

He adds that a similar steroid, DHEA, was banned by the federal government in 1985 due to safety concerns. But with the passage of the 1994 law, it reappeared on store shelves.

“If we were concerned about it in 1985, why weren’t we concerned about it in 1994?” Wadler asks.

The latest trend that capitalizes on the McGwire-androstenedione craze is making minor chemical alterations in hormone precursors. The result are substances with names like nandrolone, 19-nor-testosterone and 19-nor-androstenedione. None of these substances has undergone independent testing to examine their effects, side effects or long-term safety, Wadler says.

“I don’t know that we aren’t mortgaging young peoples’ futures because of these supplements and the way they are promoted,” he says.

The confusion over whether sports supplements are effective and safe is most evident by the professional sports organizations’ response to androstenedione. The substance is banned by the NCAA, the International Olympic Committee and the National Football League. But it is not banned by the National Basketball Assn., the National Hockey League or Major League Baseball.

An effort is underway to educate athletes, coaches and trainers about the potential problems with sports supplements, says Ambrose, who addresses teams on behalf of an NCAA education program. But consumers, says Ambrose, are “on their own.”

“It’s buyer beware. And that is unfortunate, especially in the United States, where people assume the government is regulating these products.”