This is among the first studies to show such a connection

Feb 3, 2014 10:58 GMT  ·  By

A group of investigators with the School of Public Health at the University of Michigan is among the first teams in the world to demonstrate with concrete evidence that exposure to the chemical bisphenol A (BPA), commonly found in plastic products, can lead to the development of cancer in mice.

This is one of the most critical steps in the effort to demonstrate that BPA exposure can cause cancer in humans. Though baby product manufacturers, for example, no longer use BPA in their assembly lines, other industries have been very slow to integrate the results of the latest studies into their practices.

The new study might just provide some corporations and companies with the push they need to slowly begin phasing out BPA. The research demonstrates that around 27 percent of mice born from mothers exposed to bisphenol A during pregnancy developed live liver tumors soon thereafter.

The offspring were all exposed to the chemical during gestation and nursing, exclusively from their mothers, and without ever coming into contact with this compound themselves. Details of the study were published in the February 3 online issue of the journal Environmental Health Perspectives.

The first author of the paper was Caren Weinhouse, who is a PhD student with the Department of Environmental Health Sciences at the U-M SPH. She says that the offspring of mothers that were exposed to the highest BPA levels were 700 percent more likely to develop liver cancer than the offspring of mice not exposed to this compound.

“We found that 27 percent of the mice exposed to one of three different doses of BPA through their mother's diet developed liver tumors and some precancerous lesions. The higher the dosage, the more likely they were to present with tumors,” Weinhouse explains.

“This current study showing liver tumors in mice says let's take another look at BPA and cancer in humans,” the investigator says, noting that more work is needed to clear up the intricate effects that bisphenol A produces in the human body in various concentrations.

The results of this study are extremely relevant for public health, especially when considering that nearly 90 percent of people living in the United States are contaminated with bisphenol A to a larger or smaller extent. Statistically, the potential for an explosion in cancer incidence is huge.

“A previous study that exposed adult mice to much higher doses of BPA did not show the same link to cancer development. This tells us the timing of exposure and the dosage are extremely critical in evaluating study outcomes,” says Dana Dolinoy, the senior and corresponding author of the paper.

Dolinoy holds an appointment as the John G. Searle assistant professor of environmental health sciences at U-M. She and her team plan to continue BPA studies, potentially moving up to human subjects.