Warning for future generations - Pre-natal BPA exposure may cause female infertility - Dunamis - 12-21-2010
Quote:Warning for future generations - Pre-natal BPA exposure may cause female infertility
Tuesday, December 21, 2010 by: S. L. Baker, features writer
The U.S. government is so concerned with health safety and hell-bent on supposedly protecting people from consuming certain natural foods (like raw milk), you can rest assured that Americans are not being exposed to well-documented chemical dangers in the food supply, right? Wrong.
The chemical known as bisphenol-A (BPA), which is found in plastic food containers and many baby and water bottles and also lines the inside of many food cans, leaches into food. And it has been linked time and time again to extremely serious health consequences -- including birth defects, brain dysfunction, and an increased risk of diabetes, cancer and cardiovascular disease (http://www.naturalnews.com/028748_FDA_Bisphenol-A.html). It's even suspected to cause erectile dysfunction, the politically correct term for impotence (http://www.naturalnews.com/027581_erectile_dysfunction_Bisphenol-A.html).
However, the FDA has dragged its collective feet for years on banning the chemical. Now comes new evidence that ignoring the widespread use of BPA could impact future generations. The reason? BPA exposure before birth may cause female infertility during adulthood.
A study just published online in the December 2nd issue of the journal Environmental Health Perspectives found that fertility plummeted over time in female mice that had been exposed during fetal and neonatal development. These animals were not subjected to mega amounts of the chemical, either. The doses used in the experiment were lower than or equal to human environmental exposure levels of BPA.
"Mice exposed to BPA in the womb and during nursing subsequently had fewer successful pregnancies and delivered fewer pups over the course of the study," one of the study's co-senior authors, Ana M. Soto, MD, professor of anatomy and cellular biology at Tufts University School of Medicine (TUSM) and member of the cell, molecular and developmental biology program faculty at the Sackler School of Graduate Biomedical Sciences, reported in a media statement.
At the highest dosage of three BPA amounts tested, only 60% of the BPA-exposed mice had four or more deliveries over a 32 week period, compared with 95% of animals not exposed to the chemical. Although the reproductive problems in the female mice in this study weren't apparent during their first pregnancy, later in the rodents' lives there was a significant decline in the number of offspring the animals could have.
"This finding is important because standard tests of reproductive toxicology currently consist of assessing the success of a first pregnancy in young animals. If subsequent pregnancies are not examined, relevant effects may be missed," co-senior author Beverly S. Rubin, PhD, associate professor of anatomy and cellular biology at TUSM and member of the cell, molecular and developmental biology and neuroscience program faculties at the Sackler School, said in a media release.
"In addition, the infertility effect of BPA was dose-specific in our study. The lowest and highest doses we tested both impaired fertility, while the intermediate dose did not. This phenomenon, called non-monotonicity, is a common characteristic of hormone action. In other words, chemicals have to be tested at a variety of doses in order to avoid false 'no effect' results," added co-senior author Carlos Sonnenschein, MD, professor of anatomy and cellular biology at TUSM and member of the cell, molecular and developmental biology program faculty at the Sackler School.
"Our findings are potentially of great relevance to humans because BPA is used in the production of materials people are exposed to every day, such as polycarbonate plastics and the resins used to coat the inside of food and beverage cans," said co-first author Nicolas J. Cabaton, PhD, formerly a post-doctoral fellow in the Soto/Sonnenschein laboratory at TUSM and now at the French National Institute for Agricultural Research (INRA).
The research team also pointed out that BPA has effects that mimic those of the hormone estrogen and the chemical has been shown in previous studies to increase the risk of breast and prostate cancers, abnormal behavior, and obesity. Of most concern is the fact BPA is already contaminating the human population -- it has been found in the urine of over 92% of Americans tested, with the highest levels in children and teens.
The three doses of BPA used in the new study are well within the range of human exposure and far lower than the Environmental Protection Agency (EPA) reference dose (i.e., the maximal acceptable daily dose) for the chemical. "Our results suggest that a more sensitive test, like the one used in this report should be adopted by regulatory agencies in order to uncover the true risk and possible epigenetic effects of suspected endocrine disruptors," Dr. Soto emphasized.
Editor's note: NaturalNews is opposed to the use of animals in medical experiments that expose them to harm. We present these findings in protest of the way in which they were acquired.
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