Feb. 8, 2000 (Washington) -- Androstenedione, a supplement sold in health food stores and taken by baseball great Mark McGwire, increased the amount of testosterone in men who took it for a week. That's according to a new study in the Journal of the American Medical Association, which was funded by Major League Baseball and the Major League Baseball Players Association. But that study is being criticized because the Harvard researchers did not investigate whether "andro" helped the men pump up their muscles. And some experts tell WebMD that not only is andro ineffective for this purpose, it is harmful and should be withdrawn from the market.
"Nobody cares that it raised testosterone levels," Charles E. Yesalis III, MPH, ScD, tells WebMD. "People who are buying this are not buying it for increasing their testosterone level ... they are buying it to increase their muscle mass and strength and enhance their physical appearance. The big question still remains. Are these changes of a magnitude to do that? If you asked me, does androstenedione work, I would say no."
Yesalis was not involved in this new study, but spoke out against andro last year after another study was published showing that andro raised levels of estrogen -- a female hormone -- in men who consumed it for eight weeks while involved in weight-training activities. In that study, the supplement had no effect on the men's muscle gain, compared to men who also trained and did not take andro. The study also showed that andro caused a drop in the HDL "good" cholesterol in these men.
This new study also showed increases in estrogen levels approaching those found in women, a fact that should sound alarms that andro could be bad news, especially for men and children, Yesalis says.
Andro, available without a prescription and not regulated by the FDA, received widespread publicity after it was revealed that McGwire, the home-run baseball record-holder, had used it. Although the substance is permitted in baseball, it is banned by the National Football League, the National Collegiate Athletic Association, and the International Olympic Committee.
The new Harvard study was undertaken by Benjamin Z. Leder, MD, Joel S. Finkelstein, MD, and others at Harvard University and Massachusetts General Hospital in Boston. In this study, 42 healthy men, 20-40 years old, were selected to receive one of two doses of andro or a placebo. There is no standard dose of andro. During the study period, the men's blood testosterone concentrations rose by 34% in the men taking 300 mg per day. There was no significant change in the testosterone level in the men taking 100 mg or a placebo. Their levels of estrogen also were elevated beyond what is normal for men, a situation that could potentially can cause feminizing effects in men, including breast tissue enlargement.
In an interview with WebMD, Finkelstein said the study findings did not conflict with the first study because of the differences in dosing. "The results are not different," Finkelstein says. "I think our studies are in complete agreement." He says it is too preliminary to say whether androstenedione is harmful, but notes that the observed changes in estrogen may lead to long-term health problems in men, affect growth in children, and hasten puberty in adolescents. Yet Finkelstein says it is "too preliminary" to suggest that androstenedione be withdrawn from sale to the public or that it should be more heavily regulated.
Finkelstein added he and his colleagues did not study the effect on muscle mass because dosing issues needed to be investigated first, an argument Yesalis soundly rejects, especially because previous studies have already tried to assess such an impact. Says Yesalis, "They had a responsibility to incorporate body composition and strength in their study design. If this had been the first study on this, I would not have had this complaint. But it's not."
Donald S. King, PhD, the lead author on the first study, also found fault with the Harvard research. In an interview with WebMD, King says he believes the testosterone increases seen by the Harvard team are insufficient to produce any anabolic, or muscle-building, effects. "Any positive effects of the androstenedione would be outweighed by the risks." King also faulted the Harvard researchers for failing to look at HDL, instead of just total cholesterol levels, which were unaffected. "I would like to have seen that," he says. He suspects the HDL would have been reduced in this study group, as it was among the men he studied. King is a professor in the department of health and human performance at Iowa State University.
"The one really sad thing about this, in my opinion, is that Mark McGwire's splendid or magnificent performance had nothing to do with androstenedione," King says. "There's more to hitting a baseball than how big your muscles are."
For Yesalis, there's also a message in this research and King's about androstenedione. "This is a drug and it is only classified as a supplement because of a loophole in [the law]. I don't know that it has any medical use whatsoever," Yesalis says. "What has concerned me and still concerns me is that any 8-year-old can buy this."
- According to a new study, men who took the supplement androstenedione increased their levels of testosterone.
- Outside experts criticize the study because it failed to examine whether andro helps build muscle mass.
- The potential negative side effects for men taking andro include reduced HDL "good" cholesterol and increased estrogen levels.