Study debunks androstenedione muscle benefits

June 1, 1999
Web posted at: 4:05 p.m. EDT (1955 GMT)

(CNN) -- Androstenedione, a popular supplement touted as enhancing athletic performance in men, does not increase testosterone in the blood or enhance muscle as previously believed and can be dangerous, according to a small study published in this week's Journal of the American Medical Association (JAMA).

Last year when baseball star Mark McGwire admitted he used the supplement, sales among young adults increased fivefold, according to the Office of National Drug Control Policy.

At the time, it was believed that because the body can convert androstenedione into testosterone, the supplement could increase the taker's testosterone level. There was no medical evidence to support or dispute the theory until now.

The JAMA study, conducted at Iowa State University in Ames, looked at 30 healthy men ages 19 to 29 with normal testosterone levels. Twenty of the men performed eight weeks of whole-body resistance training. During that period, 10 of the men were given 300 mg of androstenedione a day, and the others were given a placebo.

Researchers found no difference between the muscle strength or testosterone levels in the blood of those who took androstenedione and those who took the placebo.

More importantly, researchers found men who took androstenedione had raised amounts of female hormones -- known as estrogens -- in their blood. Higher estrogen levels in men can increase the risk of heart and pancreas problems. The men who took androstenedione also developed changes in blood cholesterol.

"We all talk about having good cholesterol, the HDL cholesterol, the better cholesterol. These studies showed that these levels were decreased because of this medication," said Dr. Robert Gotlin, a sports medicine specialist at Beth Israel Medical Center.

According to the study, androstenedione increased LDL cholesterol, or bad cholesterol. LDL cholesterol is believed to increase risk for heart disease and stroke.

Many body builders and athletes swear by supplements like androstenedione, but experts say it isn't the supplements that are making the difference in their physical performance.

"What happens is you get on these pills and then you get on a regimen that's much stricter than the regimen you might otherwise have gotten on, had you not been taking the pills, and it becomes a self-fulfilling prophecy," said Dr. William Rosner of St. Luke's Roosevelt Hospital.