An initial report from the Endocrine Society has raised concerns about bisphenol A use in products such as food and drink containers, toys, and medical devices, citing recent data that show the synthetic compound is linked to reproductive, behavioral, and metabolic disorders.
Dr. Laura N. Vandenberg
Although the Food and Drug Administration classifies bisphenol A (BPA) as safe to use in food containers, there have been hundreds of studies tying BPA to health problems such as “neurological outcomes, abnormal metabolism, reproductive effects as well as growth and development effects,” according to Laura N. Vandenberg, PhD, an Endocrine Society spokesperson, who spoke at a press briefing held on Oct. 23. Dr. Vandenberg explained the FDA’s 2014 position on BPA safety comes from a small subset of publicly available data, but these are not all the data on BPA, as some academic data are still under review.
The Endocrine Society recently held the news conference because they are concerned the FDA has “jumped the gun” before all the research has been published. “Even considering the fact that the data that have been presented by FDA have been interpreted by FDA as suggesting that BPA is safe, scientists still disagree,” Dr. Vandenberg said.
Dr. Heather Patisaul
However, the Endocrine Society noted there is an issue with the current literature, which can be used to interpret and report different results. Heather Patisaul, PhD, cited a joint report from the Food and Agriculture Organization of the United Nations and World Health Organization, as well as a report from the National Toxicology Program (NTP), to illustrate this problem. Both reports expressed concern about BPA safety but took different approaches and a wider viewpoint, and came to different conclusions, she said.
“These two documents both concluded that there was some concern about bisphenol A and behavior, but they identified there was a big problem with trying to pool all this literature together because the experimental protocols were different, the animals were different, the dosing was different,” she said. “It was not a very harmonious literature.”
To combat this issue, the National Institute of Environmental Health Sciences and the FDA have funded the CLARITY-BPA (Consortium Linking Academic and Regulatory Insights on BPA Toxicity) study. Dr. Patisaul said CLARITY-BPA is “the most ambitious project that’s ever been done” to study the health effects of a chemical, bringing together scientists from academic institutions, the NTP, and the FDA to help create data for risk assessment.
“The goal was to create this culture of partnership and communication between the agencies that have to make these decisions about safety and the scientists who are producing the data that’s trying to inform those assessments,” Dr. Patisaul said.
Dr. Vandenberg and Dr. Patisaul presented results from the CLARITY-BPA Core Study, which studied the effects of continuous doses of BPA in rats starting from 6 days of pregnancy; after birth, the rat offspring were fed doses of BPA for 1 year and 2 years. A second group of rats in a stop-dose group were fed BPA from early development, where the mothers were fed BPA at day 6 of pregnancy and the offspring fed BPA from birth until puberty (21 days) and followed for 1 year or 2 years. The researchers also examined 2.5 mcg/kg, 25 mcg/kg, 250 mcg/kg, 2,500 mcg/kg, and 25,000 mcg/kg doses of BPA exposure as well as continuous ethinyl estradiol exposure as a positive control.
In the FDA Core Study, there was a significantly increased incidence of mammary adenocarcinoma in the stop dose group and inflammation of the dorsal and lateral lobes of the prostate in the continuous dose group at a dose of 2.5 mcg/kg. In addition, kidney nephropathy and increased body weight in female rats in the continuous group were also seen at the 2.5 mcg/kg dose, Dr. Vandenberg noted.
“I think one of the reasons why FDA is dismissing those low-dose effects is that there’s an expectation with increasing dose, there should be an increase in an effect,” Dr. Vandenberg said.
In the low-dose range, BPA could be acting as a hormone such as estrogen, but also could be acting through other hormone receptors or as a toxicant at the high-dose range, she explained.
Dr. Patisaul also presented results of BPA-related effects on the brain and behavior in the existing literature from the TEDX Low-dose Bisphenol A project, which is a comparison of 391 in vivo and in vitro studies of BPA prior to 2009. The results showed brain and behavior was “heavily impacted” by BPA, as were organ systems such as the heart, which supports the results from the CLARITY-BPA study, Dr. Patisaul noted.
“When you think about reproducibility in the broadest sense, and you look at the effects that the FDA found at low dose, you look at the effects the CLARITY investigators found at low dose, and you go back and look at the existing literature, you see a very clear picture of BPA-produced effects on brain and behavior, female reproductive systems, and the cardiovascular system,” she said.
Dr. Patisaul is a study investigator for CLARITY-BPA.