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.
He was quick to point out that more studies are needed before any firm conclusions can be drawn, particularly because such a method of study, called histology, “is a static observation—only a snapshot.” In addition, follow-up studies may be able to better rule out other variables. In this study, an amino acid (cysteine) was added only to the organic soy diet but not the GMO (although even a cysteine-deficient diet would not explain the reproductive issues). Also, the soybeans used in both diets were purchased commercially. It is much better to use similar genetic varieties grown side by side in the same climatic conditions. Unfortunately, Monsanto doesn’t usually make the similar varieties (isolines) available for research.
The variable that Dr. Ewen wants looked at the most is the weedkiller used on GM soybeans, as he mentioned over and over that it is a probable cause of the disruption.
Is Roundup herbicide causing us reproductive problems?
Genetically modified soybeans are called Roundup Ready. They are inserted with a bacterial gene, which allows the plants to survive a normally deadly dose of Roundup herbicide. Although the spray doesn’t kill the plant, its active ingredient called glyphosate does accumulate in the beans themselves, which are consumed by rats, livestock, and humans. There is so much glyphosate in GM soybeans, when they were introduced Europe had to increase their allowable residue levels by 200 fold.
Although there is only a handful of studies on the safety of GM soybeans, there is considerable evidence that glyphosate—especially in conjunction with the other ingredients in Roundup—wreaks havoc with the endocrine and reproductive systems. “I think the concentration of glyphosate in the soybeans is the likely cause of the problem,” says Ewen.
Glyphosate throws off the delicate hormonal balance that governs the whole reproductive cycle. “It’s an endocrine buster,” says Ewen, “that interferes with aromatase, which produces estrogen.” Aromatase is required by luteal cells to produce hormones for the normal menstrual cycle, but it’s those luteal cells that have shown considerable alterations in the rats fed GM soybeans.
Glyphosate is also toxic to the placenta, the organ which connects the mother to the fetus, providing nutrients and oxygen, and emptying waste products. In a 2009 French study at the University of Caen, scientists discovered that glyphosate can kill the cells in the outer layer of the human placenta (the trophoblast membrane), which in turn can kill the placenta. The placenta cells are, in Ewen’s words, “exquisitely sensitive to glyphosate.” Only 1/500th the amount needed to kill weeds was able to kill the cells. The amount is so small, according to the study authors the “residual levels to be expected, especially in food and feed derived from R[oundup] formulation-treated crops” could be enough to “cause cell damage and even [cell] death.” Furthermore, the effect of the toxin may bioaccumulate, growing worse with repeated consumption from Roundup laden foods.
Fathers exposed to glyphosate also increase reproductive risks
In the Canadian study above, even fathers who were exposed to glyphosate before their wives got pregnant showed an increase in early delivery and abortions. In addition, a study of male rabbits showed that glyphosate can cause a reduction in sexual activity and sperm concentration, and an increase in dead or abnormal sperm.
Birth defects increased in humans and animals
Glyphosate may also cause reproductive disorders in the offspring of those exposed. When pregnant rats, for example, were exposed to glyphosate, their male offspring suffered reduced sperm production, increased abnormal sperm, and decrease in testosterone, in puberty and/or adulthood.
Other evidence of reproductive problems from GMOs
In Haryana, India, a team of investigating veterinarians report that buffalo consuming GM cottonseed suffer from infertility, as well as frequent abortions, premature deliveries, and prolapsed uteruses. Many adult and young buffalo have also died mysteriously.
Biotech advocates usually deny or try to discredit the evidence, and often attack scientists who discover it. But they rarely call for follow-up studies. With little or no money to follow up on these findings, we won’t know for sure if GMOs are the cause, or if it is glyphosate, or something else. But numerous medical doctors aren’t waiting for more research. They are telling their patients, especially those pregnant or planning to have kids, just say no to GMOs.
So if you were still eating GMOs before you read this, perhaps it’s time to take the doctors’ advice.
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