6 August 2010
Sperm quality found to plummet with BPA exposure
by Kate Melville
In the first human study of its kind, University of Michigan (UM) researchers have found that the controversial plastics chemical Bisphenol A (BPA) appears to be linked to decreased sperm quality and concentration.
Several previous studies have documented adverse effects of BPA on semen in rodents, but none are known to have reported similar results in humans. The researchers, however, point out that these results are preliminary and more study is needed.
BPA is a common chemical found in many everyday objects. Its pseudo-hormonal chemical make-up has been linked to genital deformities, infertility, epigenetic effects and a wide range of ailments and conditions.
The new study suggests that more research should focus on BPA and health effects in adults, says UM's John Meeker. "Much of the focus for BPA is on the exposures in utero or in early life, which is of course extremely important, but this suggests exposure may also be a concern for adults. Research should focus on impacts of exposure throughout multiple life stages."
Meeker's study measured BPA levels in urine and sperm concentration, sperm motility, sperm shape and DNA damage in the sperm cell. "We found that if we compare somebody in the top quartile of exposure with the lowest quartile of exposure, sperm concentration was on average about 23 percent lower in men with the highest BPA," Meeker said. The results also suggested a 10 percent increase in sperm DNA damage.
The researchers stress that further study is necessary due to the study's relatively small sample size (less than 100 men). "With a larger sample size and enhanced study design, we will be able to more definitively investigate this preliminary association in the near future," said co-researcher Russ Hauser.
Source: University of Michigan