View articles by date | ON SCIENCE Home Page | View articles by topic

The Cost of Not Regulating BPA

Effective regulation of the marketplace serves a serious function, and its failure can have serious consequences, as the melt down on Wall Street has recently demonstrated. Unfortunately, the need for effective regulation is not always so obvious before the fact.

Nowhere is this sad lesson more clearly illustrated than in the FDA’s failure to effectively regulate our exposure to the toxic chemical bisphenol A, or BPA.  Few manufactured chemicals are more widespread than BPA.  Since the 1950s BPA has been widely used in plastic food packaging, metal can linings, and clear plastic baby bottles. More than 6 million pounds of BPA are produced in the United States each year by Dow Chemical, BASF, Bayer AG and other manufacturers.  Because people ingest BPA that leaches from containers into food and drink, everyone of us is exposed to it every day.  BPA can be detected in the blood and urine of 95% of Americans.

The problem with this almost universal exposure is that in recent years hundreds of studies in laboratory animals and cell cultures have suggested that BPA poses serious risks to health, particularly to infants, who are exposed to more than 12 times as much BPA per pound of body weight as adults. This month, the National Toxocology Program expressed “some concern” that BPA alters the brain and behavior of infants and small children. Recent studies in laboratory animals have also suggested that BPA may be a cause of breast cancer in women.

This summer the FDA issued a draft report assessing the safety of BPA, based on three studies funded by the chemical industry. Ignoring the large body of research indicating potential danger and many of the studies considered by the National Toxocology Program in its assessment, this report found instead that BPA doesn’t pose a risk at the levels to which people are commonly exposed. The FDA responded that it relied on these chemical industry studies – studies which independent researchers criticize as flawed -- because the industry studies were very large, with lots of raw data to analyze.

After a firestorm of criticism by scientists who had been investigating the potential dangers of BPA, the FDA agreed to have its assessment of BPA’s safety reviewed by an independent panel of scientists, which met last week.  The independent panel proved to be a little less independent than some might have liked -- a subcommittee of the FDA science board which had overseen production of the draft report.  About 20 people spoke to the panel at the hearing, most of them opposed to the use of BPA. 


The loudest voice at the hearing, however, was not a person, but a research paper published on line that day in The Journal of the American Medical Association, the first large study of BPA in humans.  The research team, led by David Melzer of the U.K., used data collected by the Center for Disease Control and Prevention in 2003 and 2004.  Their study looked at BPA levels in the urine of 1,455 adults aged 18 to 74.  They found that individuals with the highest BPA levels were more than twice as likely to have diabetes and heart disease than those with the lowest levels.  BPA, this suggests, may cause diabetes and contribute to heart disease.

The result was not really a surprise to the researchers, who had suspected there might be a link because of the way BPA disrupts glucose metabolism.  Researchers in 2006 had tested BPA’s effects on metabolism by measuring glucose and insulin levels in mice treated with BPA, compared with control individuals treated with corn oil.  The corn oil had no effect, but BPA caused a rapid oversecretion of insulin!  The dose high enough to cause this insulin resistance was in the same range (50 micrograms/kg/day) as claimed safe by the FDA. The scary conclusion:  BPA induces diabetes in mice.

Last week’s human study was the logical next step in investigating this worrisome possibility.  The study’s result is important because it establishes that the link between BPA and diabetes is not some kind of fluke.  The FDA is quite right to point out that the result does NOT establish cause and effect.  Much more detailed clinical studies will be required to firmly establish a causal link.  What the study DOES do, however, is indicate that such a link is a distinct possibility that should be evaluated. That is how science is supposed to work, one step at a time.

But the FDA’s response to the human study -- Well, lets wait and see -- is NOT how regulation is supposed to work.  When preliminary studies suggest a serious public health hazard, cautionary steps should be taken while further research is carried out. At the very least, the review panel should recommend in its report that the FDA require a prominent warning on any bottle or can made with BPA, so that consumers who wish to can avoid them. 



© Txtwriter Inc.

Txtwriter Home Page | BACKGROUNDERS | ON SCIENCE | Text Books | Book Reviews
This website is the copyright ©1998-2013 of Txtwriter Inc. All rights reserved.