Soy During Pregnancy May Harm Male Offspring

Soy During Pregnancy May Harm Male Offspring

BALTIMORE--Soy consumption during pregnancy may adverselyaffect the sexual development of male offspring, according to an animal studydiscussed in the Feb. 15 issue of New Scientist (www.newscientist.com)and based on research that was originally printed in the November issue of MolecularMedicine (8, 11:742-9, 2002). According to New Scientist authorNicola Jones, the findings from Sabra Klein, Ph.D., and her team from JohnsHopkins Bloomberg School of Public Health, Baltimore, put the question ofwhether soy intake during pregnancy is beneficial or detrimental "back inthe spotlight."

Klein and her team originally reported that when pregnant rats were fed agenistein-enhanced diet, male offspring exhibited an increased thymus mass andreduced testosterone concentrations. However, additional information from Kleinand her team will be published in an upcoming issue of Urology, accordingto Jones. The new findings indicate male offspring of genistein-fed ratsdeveloped larger prostate glands and smaller testes. And, while the male animalsexhibited normal sperm counts and mating behavior, they were unable toejaculate. Reportedly, these effects were just as severe in the male rats thatdid not eat genistein after weaning as they were in those that continuedconsuming genistein. Researchers stated this indicates exposure in the womb andduring breastfeeding had the biggest impact on male sexual development.

"The animal study does not prove that soya has this effect on people,and no such effects have been observed in Asia where soya is a big part of manypeople's diets," Jones wrote. "But the researchers say it is enough tospark concern and deserves further study."