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Aug 272010
 

From Green Right Now Reports

Studies with lab animals have shown that BPA, the chemical found in certain clear plastics, can disrupt developing endocrine and hormone systems.

A new study with humans suggests that BPA exposure also affects mature hormone systems. Researchers looking at a group of 715 Italian men, ranging in age from 20 to 74, found subtle but measurable differences in testosterone levels, with men registering higher BPA levels also showing an uptick in hormone levels.

The group of researchers, led by the Peninsula Medical School and the University of Exeter, found that higher daily BPA exposure (as measured in urine) was “statistically associated with endocrine changes in men, specifically small increases in levels of testosterone in the blood,” according to a news release on the peer-reviewed research which is published in the latest issue of Environmental Health Perspectives.

BPA, found in polycarbonate plastic, resin liners of food cans and other containers and products, is known to mimic estrogen in the body, thereby disrupting hormone level signals in test animals. Studies have found that BPA can affect thyroid function, alter pancreatic beta-cell function and possibly play a role in cardiovascular disease.

The researchers consider this new research groundbreaking because it looks at how hormone levels are affected by every day exposures to BPA. The daily exposures of the test group ranged from about 5 micrograms per day to 8.9 micrograms.

The higher testosterone levels were not large, but were significant because they seem to confirm that BPA in the body does disrupt hormones, said Professor Tamara Galloway of the University of Exeter.

“The circulating testosterone concentrations we measured were still within a normal range for healthy men, but were statistically higher for men with higher BPA in their urine. The jury is still out on the general health effects of testosterone and how it impacts on other common diseases, we didn’t specifically measure fertility, for instance, so can’t comment on that aspect,” she said.

“BPA has been classed as a ‘hormone disruptor’ for many years, but until now most of the evidence has come from laboratory or animals studies,” Galloway added. “Here we have shown for the first time that higher exposure to BPA is associated with changes in circulating hormone concentrations in normal, healthy adult men.”

Now research needs to look at how this happens, and the potential effects on human health.