MONDAY, June 21 (HealthDay News) -- There may be more troubling
news about the ubiquitous plastics chemical bisphenol A (BPA):
Women with polycystic ovary syndrome have higher levels of the
chemical in their bloodstream, a study finds.
The ovaries of women with polycystic ovary syndrome (PCOS)
develop multiple "cysts" -- immature follicles bunching together in
lumps --and the condition can raise the risk of several conditions
including infertility, heart disease and type 2 diabetes.
In women with PCOS, higher BPA levels were also associated with
elevated levels of male hormones, according to new research that
was presented at the annual meeting of the Endocrine Society in San
Diego.
And a second abstract, also being presented at the meeting,
found that male rats exposed to BPA in the womb and while suckling
suffered long-term testicular dysfunction.
The findings add to the burgeoning, if not-yet-definitive,
evidence that BPA may have adverse health effects in humans.
BPA has been found in many plastic products, including baby
bottles and sippy cups (although most baby bottles manufactured for
the U.S. market no longer contain BPA), as well as metal linings of
some cans.
The chemical, which acts similarly to the female hormone
estrogen, has come under close scrutiny in the past several years,
with studies linking it to a host of health and developmental
problems.
In January, the U.S. Food and Drug Administration and other U.S.
health agencies announced that they were pledging $30 million
toward short- and long-term research aimed at clarifying the health
effects of BPA.
Most of the current data is from laboratory animals and shows
subtle effects of BPA on heart disease, sexual dysfunction, cancer,
diabetes and hyperactivity, as well as human studies which, among
other things, suggest a link between the chemical and aggression in
toddler girls. There is also concern that it could have an effect
on the developing fetus.
The authors of the first study, from the University of Athens
Medical School in Greece, compared blood BPA levels in 71 women
with PCOS and 100 healthy women.
Levels of BPA in the blood of healthy-weight women with PCOS
were 60 percent higher as compared with controls. BPA levels were
30 percent higher in obese women with PCOS.
And the higher the BPA level, the higher the levels of male
hormones.
But, cautioned Dr. Diana Wu, a clinical fellow in reproductive
endocrinology and infertility at Center for Reproductive Health,
University of Cincinnati, "This is an association study," cautioned
Dr. Diana Wu,. "You can't really determine cause-and-effect."
The second study found that male rats whose mothers were fed BPA
while they were pregnant and then breastfeeding produced less
testosterone than mice who had not been exposed to BPA.
The effects lasted into adulthood and after exposure had been
stopped.
The exposure levels were below those considered safe by the FDA
and the Environmental Protection Agency, the authors stated.
"We used very low doses compared to levels that the population is exposed to," said study lead author Dr. Benson T. Akingbemi, associate professor of anatomy and developmental biology at Auburn University's College of Veterinary Medicine in Auburn, Alabama. "And the effects due to BPA that were caused early in development remained into adulthood."
While this study may have looked at low levels, many BPA animal
studies use BPA levels well beyond what humans would normally
experience, thus making the totality of the evidence,
"controversial," Wu said.
In the meantime, one representative of the chemicals industry
defended BPA's overall safety.
A statement from Steven Hentges, executive director of the
Polycarbonate/BPA Global Group at the American Chemistry Council
pointed out that, "Recent reviews of the science have continued to
support the safe use of BPA in food contact applications. In
January, 2010, the FDA weighed in on BPA, noting that additional
studies on BPA are underway. Principal deputy commissioner Joshua
Sharfstein stated, 'If we thought it was unsafe, we would be taking
strong regulatory action.'" He added that other global regulatory
bodies, Health Canada, have recently completed scientific
evaluations and found BPA safe in canned food products and
beverages.
More information
There's more on BPA research at the
U.S. National Institute of Environmental Health
Sciences.