Science is a long-term process that only brings meaning when numerous, scientifically robust studies produce consistent results. But when it comes to politically loaded issues -- such as chemical safety -- a single study with a "weak association" and a small pool of subjects can capture headlines ad nauseam, creating the impression that consumers face a looming public health crisis where none really exists.
As readers of this blog and that of my chemical policy coalition know well, bisphenol A (BPA) -- a chemical used to make hard plastics and resins that line food containers -- is the subject of many such headlines. Studies on the substance come out regularly and sensationalist news stories and blog posts from BPA detractors suggest that each study provides yet more evidence that the chemical is the cause of everything from obesity to heart disease.
But what will mainstream news outlets and anti-BPA activists make of one of the more recent studies, which reports that a prior study indicting BPA as an “obesogen” (a chemical that makes you fat!) is not reproducible.
The researchers note that their study alone also doesn’t “prove” anything… not any more than the original study.
It is worth noting, that this new study included 10 times the number of subjects (in this case mice), which makes its findings a bit more meaningful. In any case, this study stands as a reminder that conclusions should be drawn not from any random study, but from the full body of research, with an emphasis on the best quality studies. That’s what scientific panels around the world have done in regard to BPA. Comprehensive studies conducted by researchers from the World Health Organization, United States, European Union, Canada, Japan, and other places have deemed the current uses of BPA safe. They all repeat the same thing: BPA risks appear negligible and the benefits outweigh those small risks.
Yet the media don't seem to understand and will likely hype the next study that claims to find a link. For example, one news report notes: "Rosenfeld and Frederick vom Saal, a curators' professor of biological sciences at MU and a leading expert in BPA research, plan to wrap up a study within the next year that should determine whether there is a connection." In reality, yet another study can't settle the issue. But if researchers can secure some "positive" finding, they certainly will capture the headlines while studies -- like this recent one -- that don't find a link attract little attention.