November 23, 2009

It’s Time To End The Anti-BPA Hysteria

By  Michael D. Shaw

Some months ago, I wrote about the misguided attacks on BPA—an important industrial chemical used in the manufacture of polycarbonate, and as a key constituent of protective coatings on metal food and beverage cans. That article outlined the science, or really the lack of science, behind the fear entrepreneurs’ push to ban this chemical, and the serious limitations of the so-called endocrine disruptor theory.

If you think “hysteria” is too strong a word, check out this whopper from the patron saint of all things anti-BPA, Fred vom Saal, referring to the supposed dangers of a plastic baby bottle: “The science is clear and the findings are not just scary, they are horrific. When you feed a baby out of a clear, hard plastic bottle, it’s like giving the baby a birth control pill.”

Somehow, though Prof. vom Saal neglected to mention that soy—a key component of many infant formulas—contains genistein, a far more potent endocrine disruptor than BPA. Nor did he tell his admirers that there are dozens of phytoestrogens in our diet, or that an endocrine disruptor is not necessarily even a bad thing. Soy, after all, seems to be protective against breast and prostate cancer.

And “hysteria” also applies to those who choose to ignore all sorts of studies giving the chemical a clean bill of health. Back in July, for example, the good news on BPA came from Health Canada—an agency usually touted by activist groups as being so much more concerned about protecting health than our own FDA. Health Canada stated that an adult would have to drink approximately 1,000 liters (264 US gallons) of water from polycarbonate water cooler bottles every day to approach the science-based safe intake limit for BPA it recently established.

Health Canada’s announcement was in line with recent assessments from eleven regulatory bodies around the world that determined BPA is safe for use in food contact products. These regulatory bodies include: the European Food Safety Authority, German Federal Institute for Risk Assessment, Danish Environmental Protection Agency, French Food Safety Authority, Swiss Office for Public Health, Food Standards Australia-New Zealand, and our own FDA.

Ironically, just before Health Canada’s findings were published, a Midwest newspaper concluded its 12-part 30,000 word attack on BPA, relying—to their everlasting regret—almost exclusively on Fred vom Saal. The timing, of course, could not have been worse, and the newspaper series came under a blistering assault from The Center for Media and Public Affairs—a nonpartisan research and educational organization which conducts scientific studies of news and entertainment media.

The fear entrepreneurs are confident that most people will not go past the sensationalized headlines, which take findings out of context, or even lie about them completely. Few journalists actually consult the published papers, or have the science background to evaluate them. Many are all too ready to believe in loony conspiracy theories whereby the government and evil industry are trying to poison the public (and kill off their taxpayers and customers, I guess.)

Sadly, the editorial standards of many scientific journals have eroded over the years. Not only can the results and methodology presented be dubious, but I have even read some articles in which the abstract—the summary portion most often read, and freely available—did not accurately reflect what was in the body of the study. Moreover, academic institutions are not above touting unpublished results, for the supposed PR benefits. A few months ago, the University of Illinois blitzed the media with the headline “Plastics chemical retards growth, function of adult reproductive cells.”

While true on its face, the headline is diabolically misleading. The reader has to get deeper into the article to find that the work described really WAS testing the effect of BPA on cells. The researcher was using cell cultures, not whole animals! A major problem with this study is that cell cultures cannot metabolize and eliminate BPA, and the BPA concentration used—10 micrograms per milliliter—is hardly a “low dose,” as characterized in the press release. In fact, such a level is orders of magnitude higher than normal human exposure.

Finally, “hysteria” is the best way to refer to the posture of Consumer Reports on BPA, as presented in the December, 2009 issue. The piece “Concern over canned foods” is rife with errors, but space allows me to mention only two.

Consumer Reports claims that dietary exposure to BPA is close to levels shown to cause harm in animal studies. Yet, the lowest oral exposures to BPA that cause adverse effects in animals are 500,000 times higher than typical human exposure.

Consumer Reports conflates oral ingestion data with animal studies in which BPA was directly injected into the blood, thus bypassing all metabolic pathways. As author Trevor Butterworth reminds us, every regulator and risk assessment in the world has rejected injection studies as a relevant method for assessing human risk from BPA, since our exposure to the chemical is through ingestion. Large, statistically rigorous, multi-generational reproductive toxicity studies have failed to reproduce the findings of injection-based studies.

Indeed, an EPA-funded rodent study recently published in Toxicological Sciences found that low-dose exposures of bisphenol A (BPA) showed no effects on the range of reproductive functions and behavioral activities measured.

In the study, researchers fed BPA to female rats during pregnancy and lactation at dosage levels approximately 40 to 4,000 times above estimated median human consumption, and the female offspring were studied for effects on behavior and reproductive function. In contrast, the well-known estrogen ethinyl estradiol had significant effects on the rodents, demonstrating the sensitivity of the study and the validity of the results for BPA.

In a pathetic effort to dismiss these results, Consumer Reports reported on its blog that the rats used in the study were insensitive to the very estrogen used as a control, which—as stated above—actually caused significant effects on the animals. Bereft of any argument, they turned to mendacity.

So, the next time you hear anti-BPA propaganda, please consider the source.