By Jeffrey Smith
September 28, 2010
If you’re still eating genetically modified (GM) soybeans and you plan on having kids, a Brazilian study may make you think again about what you put in your mouth. Female rats fed GM soy for 15 months showed significant changes in their uterus and reproductive cycle, compared to rats fed organic soy or those raised without soy. Published in The Anatomical Record in 2009, this finding adds to the mounting body of evidence suggesting that GM foods contribute to reproductive disorders (see summary at end).
Unlike women whose menstrual cycle starts automatically at puberty, female rats need to be “inspired.” Their (estrous) cycle conveniently kicks in only after being introduced to male rats. Since no males were present in this study, the females fed organic soy or no soy were appropriately untriggered (diestrus). For some odd reason, however, those fed GM soy appeared to have their ovulation cycle in full gear.
Although the researchers did not perform a check on the estrous cycle directly, their microscopic analysis of ovaries and uterus tissue showed that the hormone-induced changes (i.e. early ovulation and formation of corpus luteum) were well underway. In addition, the lining of the uterus (endometriim) had more cells than normal and the glands were dilated. In simpler terms, according to senior UK pathologist Stanley Ewen, something in the GM soy diet was “wrecking the ovary and endometrium” of the rats.
Hormonal imbalance and disease risk
Dr. Ewen speculated on the significant hormonal changes in the rats and their implications for women who eat GM soy. He said that the proliferative growth (hyperplasia) of the (endometrial) cells lining the uterus implies changes in important reproductive hormones. There might include excessive production of estrogen, follicle stimulating hormone, and luteinizing hormone, or even damage to the pituitary gland itself.
The presence of the corpus luteum, which is normally formed during the estrous cycle, means that the rats likely have higher amounts of progesterone. This hormone could increase the number of eggs released from the ovary, as well as increase their tendency to implant and be viable. If eating GM soy increased progesterone in women, this might improve their fertility.