By
Peggy Peck
WebMD Medical News
June 5, 2000 (Indianapolis) -- Fitness in a bottle has
been a popular concept since the days of musclemen kicking
sand in the faces of 98-pound weaklings. But, when Mark
McGwire admitted to taking a performance-enhancing supplement
while on his way to breaking Roger Maris' home run record,
these pills and powders began making their way into gym
bags in Little League lockers and major league clubhouses.
That, says Harvard University's Joel Finklestein, MD, may
be bad news.
Finklestein, an associate professor of medicine at Harvard,
says that androstenedione -- McGwire's supplement of choice
-- at doses of 300 mg "causes whopping increases"
in the levels of the male hormone testosterone in the blood.
That testosterone booster is what may increase muscle mass,
according to Shalendar Bhasin, MD, professor of medicine
at Charles Drew University in Los Angeles. Bhasin and Finklestein
joined other experts at the 47th Annual Meeting of the American
College of Sports Medicine in a symposium discussing the
effects of performance-enhancing supplements.
Finklestein and colleagues from Harvard recently studied
the blood taken from healthy men given either 100 mg or
300 mg of androstenedione. At 100 mg, he says, there is
no effect on blood levels of testosterone. But, even at
the lower dose, androstenedione does affect the levels of
estrone and estradiol. Both estrone and estradiol are potent
forms of the female sex hormone estrogen, which is normally
present only in minute quantities in men.
"Estradiol is so high it looks like these men are getting
ready to ovulate," Finklestein says.
Androstenedione is purified from plant sources and so is
not controlled as a drug by the FDA, says Finklestein. Asked
if he had any recommendations about its use, he tells WebMD,
"I'm very cautious about recommendations. But, in general,
I don't think that people should be taking substances that
have not be subjected to rigorous tests of both toxicity
and efficacy. And, because this substance has [a masculinizing]
and estrogenic effect, I don't think it's appropriate for
women and children."
