Soy Supplements May Decrease Sexual Drive 29126

Soy Supplements May Decrease Sexual Drive

ATLANTA--Soy supplements decreased normal sexualbehavior by 70 percent in female rats, according to a study lead by Heather B.Patisaul, Ph.D., at Emory University in Atlanta; the study has been submittedfor future publication in Hormones and Behavior.

Female rats without ovaries were given either tamoxifen (TAMOX)--a selectiveestrogen receptor modulator usually prescribed for cancer prevention--by implantor an oral soy isoflavone dietary supplement. The rats were then injected with10 mcg of estrogen and 48 hours later, injected with 500 mcg of progesterone,thus changing their "normal" hormone levels. Four hours after theinjections, the rats were measured for sexual behavior. Proceptive sexualbehavior (in the form of hopping and darting) were depressed in both the soy-and TAMOX-treated rats compared to control rats that also received injections;soy supplements decreased proceptive sexual behavior the most compared to theestrogen control group (70 percent) and the TAMOX group (50 percent). Soysupplementation also significantly reduced receptive sexual behavior (pacing andchanging posture) in rats compared to that seen in the TAMOX group and theestrogen- and progesterone-treated control rats. Patisaul concluded, "Bothsoy supplements and tamoxifen act as estrogen antagonists on both proceptive andreceptive behavior in female rats."

"We need to look at all aspects of what these compounds are doing,"Patisaul told INSIDER, "and our data suggest thatdecreased sexual performance is an effect that needs to be taken moreseriously."