The researchers measured levels of the major androgens, which include dehydroepiandrosterone sulfate (DHEA-S), androstenedione (A4), and testosterone. Monkeys who took the oral contraceptives before menopause had DHEA-S levels that were 27 percent lower than the monkeys who didn ™t take contraceptives. Levels of A4 were 53 percent lower, and levels of testosterone were 50 percent lower. These effects did not continue into menopause.

In the postmenopausal phase of the study, treatment with soy plus Premarin resulted in DHEA-S levels that were 29 percent lower than the monkeys who ate soy without isoflavones (control group) and 35 percent lower than the group eating soy with isoflavones. Total levels of testosterone were 52 percent lower than the control group and 41 percent lower than the group eating soy with isoflavones.

The researchers had suspected that the plant estrogens would also suppress androgen production. While this didn ™t prove true, they did find that these monkeys had smaller adrenal glands than monkeys that didn ™t consume the isoflavones.

The adrenal gland, located near the kidneys, uses cholesterol to make the androgen hormones and to make cortisol, a hormone associated with high levels of stress. The researchers found that while estrogen treatment lowered levels of androgen hormones, levels of cortisol increased.

This may explain the mechanism for how estrogen suppresses androgen production, said Wood.

Other researchers in the study included J. Mark Cline, Mary S. Anthony, Thomas C. Register and Jay R. Kaplan, all from Wake Forest Baptist. The research was funded by grants from the National Institutes of Health. wfubmc/