GM Free Cymru

Genetically Modified Soy Diets Lead to Ovary and Uterus Changes in Rats

Jeffrey Smith Huffington Post Posted: September 22, 2010 04:33 PM

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.

On the other hand, if women also experienced similar changes in the  uterus lining and altered hormonal levels, Dr. Ewen said it might  increase the risk of retrograde menstruation, in which menstrual  discharge travels backwards into the body rather than through the  uterus. This can cause a disease known as endometriosis, which may  lead to infertility. The disorder can also produce pelvic and leg  pain, gastrointestinal problems, chronic fatigue, and a wide variety  of other symptoms. The cause is unknown.

Dr. Ewen also pointed out that the changes in the rats, if  extrapolated to humans, might lead to abnormally heavy or longer  menstrual periods (menorrhagia).

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.

Ewen says, "If the endocrine functions of the placenta are destroyed  by glyphosate in the test tube, by extrapolation, ovarian and  endometrial function would be expected to suffer." The implications  for pregnant woman consuming glyphosate, he says, could be abortion.

Indeed, in a Canadian epidemiological study, which looked at nearly  4000 pregnancies in 1,898 couples, women exposed to glyphosate during  the three months before getting pregnant had a significantly higher  risk of abortions, especially for those above 34 years of age.

Dr. Ewen regrets that he didn't follow up a referral by a local  gynecologist about 20 years ago, who told him that women were having  abortions when the fields next door were sprayed. He doesn't know what  was sprayed.

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

Numerous indigenous people and peasant communities in Argentina have  blamed aerial spraying of Roundup on a significant rise of birth  defects. Dr. Andreas Carasco of the Embryology Laboratory, Faculty of  Medicine in Buenos Aires, decided to investigate. He exposed amphibian  embryos to a tiny concentration of glyphosate (diluted 5000 fold).  According to an excellent summary of glyphosate-related effects by the  Pesticide Action Network,

"Effects included reduced head size, genetic alterations in the  central nervous system, increased death of cells that help form the  skull, deformed cartilage, eye defects, and undeveloped kidneys.  Carrasco also stated that the glyphosate was not breaking down in the  cells, but was accumulating. The findings lend weight to claims that  abnormally high levels of cancer, birth defects, neonatal mortality,  lupus, kidney disease, and skin and respiratory problems in  populations near Argentina's soybean fields may be linked to the  aerial spraying of Roundup." Although human embryos are not directly treated with glyphosate in the  same way that Carrasco treated his amphibian embryos, it is known that  glyphosate does cross the placenta and enters the fetal circulation.

In his article, Dr. Carrasco describes some disturbing findings in  Argentina, where more than 50 million gallons of glyphosate-based  herbicide is used on more than 45 million acres of GM soy.

In Argentina, an increase in the incidence of congenital malformations  began to be reported in the last few years. In Co´rdoba, several cases  of malformations together with repeated spontaneous abortions were  detected in the village of Ituzaingo´, which is surrounded by GMO- based agriculture. These findings were concentrated in families living  a few meters from where the herbicides are regularly sprayed.

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

The changes in the rat uterus and ovulation cycle are by no means a  smoking gun. But they are now part of a pattern of multiple  reproductive disorders found in GMO feeding studies. Professor Vyvyan Howard, a toxico-pathologist of the University of  Ulster, says, "Several new hazards can now be identified." The growing  body or research showing problems, he says, "provides ample evidence  that the producers of GMO crops are not performing risk assessments  for some of the hazards that independent scientists are identifying  and testing." Dr. Howard, who specializes in the effects of toxins on  the fetus and infants,  asks, "What will be the effect on the fetus in  the womb of women eating these foods? This needs to be tested."

The few tests that have been done on animals are more than sobering.  In April 2010, researchers at Russia's Institute of Ecology and  Evolution of the Russian Academy of Sciences and the National  Association for Gene Security found that after feeding hamsters GM soy  for two years over three generations, by the third generation most  lost the ability to have babies. They also suffered slower growth, a  high mortality rate among the pups, and a high incidence of a rare  phenomenon of hair growing inside their mouths.

When I reported the results of the hamster study, I included the  following review of other GMO-related reports of reproductive disorders:

In 2005, Irina Ermakova, also with the Russian National Academy of  Sciences, reported that more than half the babies from mother rats fed  GM soy died within three weeks. This was also five times higher than  the 10% death rate of the non-GMO soy group. The babies in the GM  group were also smaller (see photo) and could not reproduce. In a telling coincidence, after Ermakova's feeding trials, her  laboratory started feeding all the rats in the facility a commercial  rat chow using GM soy. Within two months, the infant mortality  facility-wide reached 55%.

When Ermakova fed male rats GM soy, their testicles changed from the  normal pink to dark blue! Italian scientists similarly found changes  in mice testes (PDF), including damaged young sperm cells.  Furthermore, the DNA of embryos from parent mice fed GM soy functioned  differently.

An Austrian government study published in November 2008 showed that  the more GM corn was fed to mice, the fewer the babies they had (PDF),  and the smaller the babies were. Central Iowa Farmer Jerry Rosman also had trouble with pigs and cows  becoming sterile. Some of his pigs even had false pregnancies or gave  birth to bags of water. After months of investigations and testing, he  finally traced the problem to GM corn feed. Every time a newspaper,  magazine, or TV show reported Jerry's problems, he would receive calls  from more farmers complaining of livestock sterility on their farm,  linked to GM corn.

Researchers at Baylor College of Medicine accidentally discovered that  rats raised on corncob bedding "neither breed nor exhibit reproductive  behavior." Tests on the corn material revealed two compounds that  stopped the sexual cycle in females "at concentrations approximately  two-hundredfold lower than classical phytoestrogens." One compound  also curtailed male sexual behavior and both substances contributed to  the growth of breast and prostate cancer cell cultures. Researchers  found that the amount of the substances varied with GM corn varieties.  The crushed corncob used at Baylor was likely shipped from central  Iowa, near the farm of Jerry Rosman and others complaining of sterile  livestock. 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