From the article:
“Our findings suggest that it might be important for women taking estrogen after menopause to also take androgen supplements – which can include testosterone,”
Half of the monkeys were given oral contraceptives, which contain estrogen, in their diets for 26 months. All animals then had their ovaries removed to make them menopausal.
For the next three years, the animals were divided into three groups based on diet. One group ate soy that didn’t contain isoflavones, which are natural plant estrogens; one group ate soy with the isoflavones intact, and one group’s diet was soy without isoflavones and Premarin [conjugated estrogen], or estrogen therapy, added.
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.