Epigenetic mechanisms

Did you know that just one exposure of a pregnant woman to synthetic chemicals such as bisphenol A (BPA), fungicides, and even diethylstilbestrol (DES), could affect her children for several generations and may even cause permanent genetic change?  What we do now could cause cancer, diabetes, obesity, or other damage in our children, grandchildren, and great-grandchildren.  This transgeneration change is explained by the science of epigenetics.  For more information about epigenetics, see the Sources and Resources listing below.  For a very brief idea about what it is, I liked how one YouTube video [see below for video] summed up epigenetics:  The Genome is the hardware, it does the work.  The Epigenome is the software, it tells the Genome what to do and how to do it.  The catch here is that the Epigenome can be affected by our environment, both positively and negatively.

New epigenetic study

A recent study of male rats by Dr. David Crews of the University of Texas-Austin and others has found that a single exposure to a common-use fungicide (vinclozolin) affected physiology, behavior, and metabolism to the extent that descendants three generations later responded differently to stress.   The timing of the exposure is critical to the extent of the effect– the greatest developmental sensitivity to this type of exposure is during the prenatal, immediately postnatal/infant, and adolescent/puberty periods.  Yes, the one-time exposure to vinclozolin caused physical and behavioral changes in the third generation!  In fact, Dr. Crews says that the effects may be permanent; he sees no evidence that they will ever disappear.  How common are these chemicals that can cause permanent epigenetic damage?  What about this fungicide, the chemical used in this study?  Vinclozolin, an endocrine disruptor with antiandrogenic effects, is used “to control diseases, such as blights, rots and molds in vineyards, and on fruits and vegetables such as raspberries, lettuce, kiwi, snap beans, and onions. It is also used on turf on golf courses.”  Any of those sound familiar?  How many of us have already been exposed, maybe more than once, to this endocrine disruptor?  What other chemicals have we been exposed to that may have already affected our descendants?

Diethstilbestrol (DES) affects children, grandchildren, and great-grandchildren

Mike Adams of Natural News.com interviewed Dr. Crews about his groundbreaking study, the first study that actually demonstrates transgenerational cause and effect.  This is not an observational study; it does show causation.  The whole field (of epigenetics) is fascinating, but what really caught my attention in this interview was the example used by Dr. Crews to demonstrate the significance of epigenetic transgenerational effects–diethylstilbestrol (DES). DES is a synthetic nonsteroidal estrogen that was given to about 3 million pregnant women in the U.S.–and many others around the world–in the 1940s, 50s, and 60s because it was thought to be able to prevent miscarriage.  Although by 1953, it had been shown that DES did not prevent miscarriage, physicians continued to prescribe it until the FDA issued a warning in 1971.  Some European countries continued prescribing DES until the early 1980s.   You may be too young to remember when this was in the news, but I remember how tragic the news was at the time.  What was the tragedy?  Although the women who took DES were at a slightly greater risk of breast cancer, the real tragedy of DES was for the children born of those pregnancies.  It has been well documented that the daughters were at increased risk of developing cancers of the vagina and cervix, cancers more typical of menopausal women.  Sons were at increased risk of developing testicular and other cancers more typical of older men.   Most of the cancers began to appear when the children were between 14 and 22 years of age.  Cancer was not the only damage caused by DES.  Daughters who were exposed to DES in utero have up to a 33 percent increase in incidence of structural reproductive abnormalities, which can increase the risk of infertility and adverse pregnancy outcomes. Sons have a 300 percent increase in incidence of genital structural abnormalities, some of which are associated with an increased risk of testicular cancer.  According to Dr. Crews, the children, grandchildren, and now even great-grandchildren have shown a similar increased risk of damage.  He says that DES is the best human example of an endocrine disruption compound with a transgenerational effect. [The discussion of DES is at 38:49 in the video interview.]

Other endocrine disruptors

If DES and vinclozolin have such a devastating effect on our epigenome, what are other common endocrine disruptors that could have (or may have already had) a similar effect?  Here are some that you probably have heard about:  dichloro-diphenyl-trichloroethane (DDT), polychlorinated biphenyls (PCBs), bisphenol A (BPA), phthalates, and atrazine.

Is it hopeless? What can we do?

My mother and grandmother made dietary decisions that have affected me!  I made decisions that affected my children.  You may be making decisions that will affect your children and grandchildren.  We should remember, however, that the epigenetic effects on our children don’t need to be all bad.  We can benefit our children, grandchildren, and all our descendants by eating nutrient-dense REAL foods, following a healthy lifestyle, and making a sincere effort to avoid unnecessary chemicals.  We should all care about what we eat, what we breathe, what we drink, what medicines we take, and what we touch.  Our children’s and grandchildren’s health, as well as our own today, depends on it.

Sources and more information about Epigenetics and Diethylstilbestrol:

Proceedings of the National Academy of Sciences of the United States of America (PNAS), Epigenetic transgenerational inheritance of altered stress responses
Natural News, Red alert for humanity: Chemical damage can be inherited by offspring through unlimited generations
Time Magazine, Why Your DNA Isn’t Your Destiny
Epigenetics, an excellent video explanation of the power of epigenetics
NOVA, Epigenetics
The University of Utah, What is Epigenetics?
Johns Hopkins Medicine, Backgrounder: Epigenetics and Imprinted Genes
Food Renegade, Interview with Dr. Catherine Shanahan On Deep Nutrition and Genetic Expression
Wikipedia: Diethylstilbestrol
American Family Physicians, Diethylstilbestrol Exposure
CDC DES Update Home

Here is the YouTube video I mentioned above.  It explains succinctly the power of epigenetics.




Photo credit: Epigenetic mechanisms