Poodle Skirts and Leisure Suits: Sorting Out The Science on Bisphenol A

Confused about the science on bisphenol A (BPA)? You’re not the only one. Competing conclusions about BPA’s safety can make even the most conscientious consumer or policymaker scratch her head.

In the last decade, a raft of academic researchers have reported study results showing that BPA can lead to cancer, early puberty, and other troubling health problems at incredibly low doses. But industry and some government scientists have conducted studies that fail to find these problems. What’s going on here? Does the science support taking action now on BPA? We think so, and here’s why.

Shall we bring back the poodle skirt?

Two industry-funded studies (1, 2) used by the FDA and the European Food Safety Authority (EFSA) to evaluate the safety of BPA rely on techniques that go back to the 1950s. They dose laboratory animals with BPA and test for a limited number of effects, such as major changes in tissue weight and appearance. By contrast, the hundreds of academic and government studies on BPA ignored by FDA and EFSA use updated techniques and find effects the industry-funded researchers didn’t even look for—reproductive problems, neurological and behavioral effects, and changes to growth in prostate and breast tissue leading to precancerous lesions.

Those insensitive rats.

Two recent EPA studies (3, 4) cited as indicating that BPA is not harmful did use more up-to-date techniques, but used rats known to better tolerate hormone-disrupting chemicals like BPA. The researchers set out to test the effects of low doses of BPA that had previously shown effects on mice. Yet they failed to account for the rats’ reduced sensitivity, using too low of a dose of BPA to replicate the previous studies.

“Good” science—from the 1970s.

The 1970s brought us not only disco balls and leisure suits but also scandals involving serious misconduct in industry labs leading ultimately to a criminal investigation and prison sentences. One of the results—the establishment of protocols for “Good Laboratory Practices,” a set of procedures on laboratory animal care, data collection, and other basic practices established as a response to this misconduct at private research companies. These protocols—still the norm today for industry research and used in the industry—funded studies on BPA, are designed to provide quality assurance but do not ensure that research has appropriate design or execution. And they don’t hold a candle to the peer review process, used by other researchers, that provides a critical analysis of research before publication.

The National Toxicology Program used the vast literature from academic and government researchers to conclude that there is concern about exposure to BPA. The Food and Drug Administration, on the other hand, has so far stuck with two industry studies that use “good laboratory practices” but fail in both study design and execution to properly assess the effects of BPA. FDA and other policymakers can choose to keep their faith in 1950s science, or they can open their eyes to the hundreds of studies using up-to-date techniques and showing that today’s exposure to BPA is a matter for serious concern and swift action. 

1.    Tyl R, CB Myers, MC Marr, BF Thomas, AR Keimowitz, DR Brine, MM Veselica, PA Fail, TY Chang, JC Seely, RL Joiner, JH Butala, SS Dimond, SZ Cagen, RN Shiotsuka, GD Stropp, and JM Waechter. 2002. Three-generation reproductive toxicity study of dietary bisphenol A in CD Sprague-Dawley rats. Toxicological Sciences 68:121-146.

2.    Tyl R, Myers C, Marr M, Sloan CS, Castillo N, Veselica MM, et al. 2008. Two-generation reproductive toxicity study of dietary bisphenol A (BPA) in CD-1 (Swiss) mice. Toxicological Sciences 104:362-384.

3.    Howdeshell K, J Furr, CR Lambright, VS Wilson, BC Ryan and LE Gray. 2008. Gestational and lactational exposure to ethinyl estradiol, but not bisphenol A, decreases androgen-dependent reproductive organ weights and epididymal sperm abundance in the male Long Evans hooded rat. Toxicological Sciences 102:371-82.

4.    Ryan B, AK Hotchkiss, KM Crofton, and LE Gray. 2009. In utero and lactational exposure to bisphenol A, in contrast to ethinyl estradiol, does not alter sexually dimorphic behavior, puberty, fertility, and anatomy of female rats. Toxicological Sciences Online October 28, 2009.