BPA (bisphenol A) has gotten a good deal of press coverage in recent years thanks to over a thousand studies looking at its effects on different parts of the body and to its astonishing ubiquity. BPA is found in thousands of products, and more than 7 million tons of the chemical is produced every year. It’s also found at detectable levels in almost all of us.
You probably recall the controversy over BPA earlier this decade, when the US Food and Drug Administration banned its use in baby bottles and sippy cups, but continued to allow it in food packaging. China, Canada, and the EU have restricted its use in some applications, and in 2015 France banned it from all food contact uses. Canada was the first country to label BPA toxic, and the European Chemical Agency recently classified BPA as a “chemical of very high concern.”
The American Academy of Pediatrics made headlines this summer when it issued a statement calling for stricter regulations of a number of food additives and packaging materials, including BPA in its list of chemicals that pose risks to children’s health.
Despite these concerns, BPA is still commonly used in American food packaging. But why?
Investigating BPA’s Safety: Diverging Methods
Though more than a thousand animal studies and a hundred epidemiological studies have linked BPA to numerous health impacts, the U.S. Food and Drug Administration (FDA) has steadfastly maintained its safety, pointing to its own studies, which differ markedly in design from those academic scientists use. In order to bridge this methodological gap, the National Institute of Environmental Sciences (NIEHS), the National Toxicology Program (NTP), and the FDA devised a landmark two-prong study using both FDA protocols and academic scientific methods.
The Consortium Linking Academic and Regulatory Insights on BPA Toxicity, commonly referred to as CLARITY-BPA, was a six-year long study analyzing the effects of BPA at varying doses on rats using both the standard FDA methods and a variety of techniques that evaluated BPA’s effects on different parts of the body, including the endocrine, immune, reproductive, and cardiovascular systems, as well as effects on cancer development.
It’s vital to understand how the FDA’s methods for evaluating safety differ from those academics use to determine the health effects of chemicals.
The FDA released its half of the findings in 2018 and affirmed its stance that BPA has “minimal effects” on the rodents they studied. Headlines in the press assured consumers of the material’s safety. Many academics involved in the study, however, found this announcement extremely premature and misleading, as it did not take into account any of the academic researchers’ findings, which in many cases bore out the concerns that led to the study in the first place. The two sets of findings will not be integrated until the NTP issues a final report in late in 2019.
To comprehend the discrepancy between the data sets, it’s vital to understand how the FDA’s methods for evaluating safety differ from those academics use to determine the health effects of chemicals. According to Frederick vom Saal, an endocrinologist who has been studying BPA for decades and who participated in CLARITY, the FDA relies on evaluative techniques it developed in the first half of the twentieth century that use measures of toxicity he calls “extremely crude and simplistic.”
FDA techniques evaluate obvious signs of disease like the development of tumors or changes in organ weight. These “endpoints,” as they’re referred to by researchers, miss more subtle alterations to organs like the brain or of complex systems like endocrine function.
Academic scientists, on the other hand, use more sophisticated evaluation tools, such as computer scans or antibodies researchers have linked to important changes at the molecular level. Endocrinologists, vom Saal explains, know that in the case of hormone receptors, “one binding event can lead to thousands of molecules being produced in the cell that will produce huge consequences.”
Interpreting CLARITY’s BPA Study Results
Academic researchers participating in CLARITY found that the lowest doses of BPA altered brain structure, measures of cardiovascular health, and ovarian function. At higher dose levels researchers observed memory and learning deficits. To date, eight of the fourteen academic researchers have published their findings; forthcoming publications will analyze BPA’s effects on diabetes, obesity, reproductive organs, and mammary and prostate glands.
Complicating matters further, vom Saal contends, the framework toxicologists at the FDA use to evaluate data fundamentally dismiss the low-dose effects that he and other academic researchers have found in thousands of experiments, including CLARITY. Even the FDA’s simpler methods revealed increased prevalence of mammary tumors and prostatitis, a precursor to cancer at the lowest dose levels. But because the toxicological model relies on the assumption that to be toxicologically significant, a compound must have increased effects at higher doses — which BPA doesn’t — the FDA report writes off the low-dose effects they found as insignificant.
Ultimately, no matter how many times research shows low-dose effects, if BPA does not have what are termed “acute” effects at very high doses, then the FDA model will continue to proclaim it safe. Unfortunately, the low dose comparable to human exposure is what produces the significant health impacts found by academic investigators.
Jerry Heindel, who worked for twenty years at NIEHS, helped to develop the CLARITY study in an effort to refine and update the methods of regulatory risk assessment. He was disheartened by the FDA’s dismissal of the low-dose health effects their own study found. “The fact that they tend to not believe in low-dose effects,” says Heindel, “is a real problem for academic researchers and for doing a good job of interpreting the results of this study. We didn’t realize they were going to be so entrenched in the old toxicology paradigm of linear dose responses and would not really pay much attention at all to low dose effects.”
Academic researchers found that the lowest doses of BPA altered brain structure, measures of cardiovascular health, and ovarian function. At higher doses, researchers observed memory and learning deficits.
In addition, several researchers have raised objections to the animals used in the study, which are exceptionally insensitive to estrogenic chemicals, like BPA. According to vom Saal, the Sprague-Dawley rats used in CLARITY are the animal of choice at the FDA, and they were selected for CLARITY not because they were especially appropriate, but because it’s what they always use. Vom Saal says toxicology guidelines dictate that experiments use the most sensitive animal and calls the choice of the Sprague-Dawley rat “crazy.”
Thomas Zoeller, who has researched thyroid function for decades, likewise found the animals uniquely insensitive to low levels of thyroid hormones, which have significant developmental effects on other animals as well as humans. To get a baseline for their responsiveness, in addition to the group of animals dosed with BPA, he created a comparison group given a drug known to lower thyroid hormone levels in other animals.
“I’ve never seen anything like it,” he remarked. “It’s not precedented that a rodent model would exhibit thyroid hormone insufficiency to this extent during development and not exhibit robust effects on brain development.” Though he found no effect of BPA on thyroid levels or the expected developmental effects from low thyroid, he explains, “The bottom line is BPA did not affect the thyroid, but these animals don’t seem to have a thyroid system that is like other animals or like people.”
Dr. John Bucher, Senior Scientist at NTP, will oversee a small team charged with synthesizing the two halves of the study. He explained that the team will conduct a systematic review to develop “rigorous and unbiased assessment of study conduct and methodologies.” Vom saal is concerned that the NTP will bow to the FDA and downplay academics’ findings, calling it a “wolves guarding the hen house scenario.”
Don’t Use It If You Don’t Have To
While the FDA’s findings satisfy their criteria for safety, the consensus from academic researchers is that CLARITY has only confirmed what decades worth of academic literature has been telling us. BPA may be having subtle but significant effects on our health, most especially on fetuses and children, whose size and developing bodies make them more susceptible to hormone-disrupting chemicals. We can’t know precisely how these compounds will affect individual disease risk, but the data suggests avoiding BPA when possible is a sensible precaution.
BPA may be having subtle but significant effects on our health, especially on fetuses and children, whose size and developing bodies make them more susceptible to hormone-disrupting chemicals.
One of the things the CLARITY study helps bring into focus is that current methods for evaluating safety are likely not catching some of the more subtle ways the chemicals we’re exposed to every day may affect our health. Thomas Zoeller cautions, “I think it’s very important for people to recognize that their safety, the public safety, is dependent on the weight of a rat’s uterus. How can anybody think that’s appropriate?”
“What people need to know,” Zoeller explains, “is that the traditional system of safety determination doesn’t work fully. If it’s gonna kill you, they’ll find it. But If it affects diabetes, obesity, cardiovascular disease, or cognitive function they’re not going to catch it.” He notes that the design of CLARITY, if it takes into account these additional endpoints, “has the ability to improve our regulatory system and public health safety.”
In the meantime, he’s telling friends and family to avoid plastics whenever possible: “Don’t use it if you don’t have to!” he warns.
Unfortunately avoiding BPA exposure altogether can be very difficult, as it’s in so many types of packaging as well as the tubing used by dairy operations and our water pipes. However, some straightforward measures can significantly cut your exposure.
How to Avoid BPA Plastic Effects
Easier said than done, of course. First, we all need to pressure companies to cut their use of plastic chemicals. Vote with your dollars by choosing non-plastic options and contact companies about finding safer, non-plastic alternatives. When petitions or bills come up, be sure to let legislators know you care about reducing the use of BPA and other hormone-disrupting chemicals. Share your concerns about plastics with friends and family as well. As more people understand the risks of these all-too-common compounds, the more industry will feel the need to respond.
In the meantime, in the absence of more comprehensive safety regulations, protecting yourself is up to the consumer. Here’s how to reduce your exposure to the compounds in plastics:
- Cut plastic use overall. Buy food without packaging and choose better options like glass and metal. These containers last longer, can safely be put in the dishwasher, and don’t leach chemicals into food. Avoid shopping in dollar stores.
- Nix the plastic bottled beverages. Look for glass bottles or make your own drinks and serve in ceramic, glass, or metal.
- Skip the plastic wrap and baggies. Reusable wraps let you avoid the plastic and minimize waste. Store leftovers and tote lunches in sturdy and long-lasting metal or platinum silicon.
- Avoid purchasing canned food. Though canned goods are metal on the outside, most are lined with plastic resins. Look for glass packaging, opt for fresh or dried, or can your own.
- Don’t heat plastics in the microwave or run them through the dishwasher. Heat increases how much BPA leaches into food.
- Avoid touching receipts and don’t let kids handle them. Most thermal printed receipts contain BPA or BPS and studies have shown we readily absorb it into our skin.
- Don’t be lulled into a false sense of security by a label saying “BPA-free.” When studies linking BPA to health problems began coming out, the plastics industry quickly replaced BPA with other, less-studied chemicals, like BPS. As researchers investigate what they refer to as “regrettable substitutions,” they are finding that in many cases the effects are even more pronounced than BPA’s.
BPA Plastic in Our Bodies
Research is ongoing about how these chemicals migrate into our food. Though many of us have gotten the message not to microwave our food in plastic containers, it may seem less intuitive that the plastic bags our cereal or coffee come in may also be shedding tiny particles of plastic.
The good news is that we appear to get these compounds out of our systems quite quickly. A 2011 study found that avoiding cans, restaurant food, and plastic packaging for just three days lowered levels of BPA and the phthalate DHEP 50-95% depending on the initial levels of exposure. If we take steps to limit our use of plastics and companies continue to seek safer alternatives, the prevalence of these compounds and the diseases they may promote could begin to decline.