AMES, Iowa--Results from two current studies suggest that androstenedione (andro) may not only be ineffective as a supplement to build muscle in older men, but may also adversely affect blood cholesterol levels.
In the November issue of The Journal of Clinical Endocrinology & Metabolism (JCEM) (85(11):4074-4080, 2000), researchers conducted a four-week, double-blind, randomly assigned study on 55 men between the ages of 30 and 56. The subjects consumed either 100 mg of andro or a placebo three times a day. Both groups had unchanged free testosterone levels, but the andro group showed a substantial increase in levels of dihydrotestosterone (the by-product of testosterone conversion), which researchers said could lead to prostate problems. The study noted there was no increase in prostate-specific antigen levels, a marker that signals an enlarged prostate and prostate cancer.
The researchers, led by Gregory Brown of Iowa State University, also found no relationship between age and changes in serum androstenedione, free testosterone or estradiol concentrations in those taking andro; however, serum dihydrotestosterone response to andro supplementation was found to be related to age. In addition, concentrations of high-density lipoprotein (HDL) cholesterol were decreased by 10 percent in subjects taking andro.
A separate study appearing in the Nov. 13 Archives of Internal Medicine confirmed that andro may be ineffective in older men, but did not mirror the JCEM study's blood cholesterol level results. In a 12-week, random, double blind study, androstenedione and androstenediol supplementation briefly raised testosterone levels, but the increase was fleeting. At the end of the 12 weeks--after consuming 200 mg/d of andro-testosterone levels in the 50 male subjects (ages 35 to 65) returned to baseline.
Moreover, it was found that HDL levels were increased by 6.5 percent (compared to 5.1 percent in the placebo group). Nonetheless, there was still a 12.3-percent decrease found in HDL/LDL ratio.
The researchers, led by Craig Broeder, Ph.D., from East Tennessee State University, concluded that testosterone precursors do not enhance adaptations to resistance training and may produce unfavorable alterations in blood lipid levels when consumed in dosages recommended by manufacturers.
Also, taking more than the labeled amount may not be wise. "Even if you were to take an exorbitant amount [of andro], you are not likely to see [positive] results," said Conrad Earnest, Ph.D., a researcher at the Cooper Institute of Aerobics Research and a co-author of the Broeder study. "Statistically, you get a small bump in testosterone, but you get these exponential alterations in estrogen." He added that this additional estrogen throws off the body's natural hormonal balance, which may lead to potentially harmful side effects after long-term use.