ATLANTA -- The fountain of youth apparently does not yet come in a pill.
Widely used DHEA supplements and testosterone patches failed to deliver their touted anti-aging benefits in one of the first rigorous studies to test such claims in older men and women.
The substances did not improve the participants' strength, their physical performance, or certain other measures of health.
``I don't think there's any case for administering these" to elderly people, said Dr. K. Sreekumaran Nair of the Mayo Clinic, lead author of the study, published in today's New England Journal of Medicine.
DHEA, a steroid that is a precursor to the sex hormones testosterone and estrogen, is made by the body, but levels decline rapidly after age 25. DHEA supplements are marketed as rejuvenating agents, and US sales hit $50 million last year.
Testosterone is available by prescription only. But the Food and Drug Administration classifies DHEA as a supplement, meaning it can be sold without meeting the same safety and effectiveness standards as a drug.
Some athletes use DHEA and testosterone to try to boost performance, often in violation of athletic association rules.
The NFL and other professional sports have banned DHEA. Cycling officials have moved to strip the Tour de France title from winner Floyd Landis, after a French laboratory found elevated testosterone levels in his urine.
Apart from this type of use, scientists have wondered whether the substances might help older people. Studies with rodents offered tantalizing results that indicated DHEA seemed to decrease fat and fight diabetes and heart disease.
But there have been few rigorous scientific studies in humans. A French study of DHEA in 280 elderly people, reported in 2000, found that the only benefit was an increase in female libido.
A Dutch study this year found no benefit of DHEA in 100 men 70 and older.
The new study was done by researchers at the Mayo Clinic in Minnesota and the University of Padua in Italy.
Over two years, the researchers studied 57 women and 87 men, all of them at least 60 years old.