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17 April 2014 12:48 pm ,
Vol. 344 ,
Officials last week revealed that the U.S. contribution to ITER could cost $3.9 billion by 2034—roughly four times the...
An experimental hepatitis B drug that looked safe in animal trials tragically killed five of 15 patients in 1993. Now,...
Using the two high-quality genomes that exist for Neandertals and Denisovans, researchers find clues to gene activity...
A new report from the Intergovernmental Panel on Climate Change (IPCC) concludes that humanity has done little to slow...
Astronomers have discovered an Earth-sized planet in the habitable zone of a red dwarf—a star cooler than the sun—500...
Three years ago, Jennifer Francis of Rutgers University proposed that a warming Arctic was altering the behavior of the...
- 17 April 2014 12:48 pm , Vol. 344 , #6181
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Andro Bumps Up Testosterone Levels
9 February 2000 7:00 pm
In 1998, baseball player Mark McGwire made headlines by hitting 70 home runs in one season, shattering the long-standing record. At the time, he was regularly--and legally--taking androstenedione, a steroid that many athletes use for its alleged muscle-building properties. Now researchers have shown that the body converts andro to testosterone, a finding certain to fuel the debate over whether andro, like testosterone, should be banned from baseball or even outlawed.
According to endocrinologist Don Catlin of the University of California, Los Angeles, andro is legal because it has not been proven to act as an anabolic (in other words, muscle-building) steroid, and because it is allegedly found in the bark of some trees. Under the dietary supplement act of 1994, substances "found in nature" can be sold as supplements, provided no medical claims are made on the label. However, many sports organizations, such as the International Olympic Committee and the National Football League, have banned andro because of its similarity to testosterone, a known performance enhancer that also causes liver damage, stunted growth, high cholesterol, and prostate cancer.
Major League Baseball took a different approach to the problem, funding a study by endocrinologists Joel Finkelstein and Benjamin Leder of Massachusetts General Hospital in Boston. The goal was to determine what actually happens to andro when it gets in the body. For 1 week, Finkelstein and Leder gave 13 men a placebo, 15 a 100-milligram pill, and 14 a 300-milligram pill--doses within the range that athletes are thought to take. Both groups that received andro showed significant increases in estradiol--a potent female hormone that causes abnormal breast development in men. The men who took the larger amount of andro also had a 30% rise in blood levels of testosterone, the researchers report in the 9 February Journal of the American Medical Association.
Doctors are divided over whether andro actually does what athletes believe it does--help them build muscle. Douglas King, an endocrinologist at Iowa State University, believes the supplement is too weak, pointing out that of the 14 men who took the higher dose of andro, 10 of them still had testosterone levels in the normal range. Catlin, on the other hand, believes that higher doses taken for longer than a week would increase muscle size measurably. However, all agree that no one should take androstenedione for nonmedical reasons. "Certainly the side effects outweigh any possible benefit," says King.