You may have heard of BPA and wondered what it is and why it often seems to be accompanied by the phrase “health concerns.” In fact, BPA surrounds us and is detectable in most human bodies.
BPA is a chemical used in plastics manufacturing since the 1960s—including ubiquitous products like water bottles and food containers. While the FDA’s stance is that the BPA levels observed in food products are low enough to be considered safe, recent research indicates that the chemical may be harming our health and that past studies have underestimated the amount of BPA that’s entering our bodies.
Here’s what the most recent research says about BPA, along with some tips from health experts on how to avoid it.
What is BPA?
BPA stands for bisphenol A, an industrial chemical used to make polycarbonate plastics and epoxy resins. The former is typically used in food and beverage containers and many other consumer products. The latter is used to coat the inside of metal products, like food cans and water supply lines, to protect food and water from direct contact with the metal. BPA provides plastic with rigidity and resistance, and is transparent, which is why it’s so often used in, for example, the manufacturing of water tanks.
Its effectiveness means that BPA is found almost everywhere. According to a review published in Comprehensive Reviews in Food Science and Food Safety in 2018, the global consumption of BPA products was estimated at 7.7 million metric tons in 2015 and is expected to reach 10.6 million metric tons in 2022.
Despite the FDA's position, research has raised public-health concerns over BPA exposure, and the FDA continues to monitor the research.
Possible health effects of BPA
As noted in the aforementioned review, BPA is an omnipresent environmental contaminant and can be found in air, soil, and water. Sources of human exposure include occupational (mainly for those who work in the synthesis of BPA), environmental, and food consumption.
Concerns mainly arise from overexposure through food consumption, with canned foods and beverages as the main source of dietary exposure for all age groups. Various studies have found that BPA can transfer into food when it’s heated inside a container, when it comes in contact with alkaline or acidic substances, when plastic containers are overused, or when microwaved. The authors of the review noted that this kind of exposure is “most worrisome” because it can reach people across age groups, and can occur for long durations without detection. According to the review, a study conducted on the distribution of BPA in humans found that the chemical was detectable in almost all human tissue.
Research shows that BPA is an endocrine disruptor, and studies have suggested that exposure during pregnancy can affect the brain development and behavior of newborns. Evidence indicates that BPA exposure may lead to increased risks of anxiety and depression, autistic behaviors, and impaired memory and learning in children. Other studies have suggested that early BPA exposure may be linked to hyperactivity in young people.
In addition, there is strong evidence that BPA exposure can influence the onset of meiosis in ovaries. Animal studies have also suggested that BPA can disrupt uterine function due to endometrial cell proliferation, decrease uterine receptivity, and increase implantation failure.
A number of epidemiological analyses and animal studies have provided evidence indicating that BPA may increase the risk and worsen the morbidity and mortality of cardiovascular diseases, including coronary heart disease, angina, heart attack, hypertension, and peripheral arterial disease.
The review also cites evidence that BPA exposure is associated with a higher incidence of various cancers, including breast, uterus, ovarian, prostate, and testicular. The proposed mechanism behind this is BPA’s estrogenic activity. The authors of the review point out that, although evidence has shown that this can cause many health issues including obesity and neurological toxicity, BPA’s apparent carcinogenic properties require more examination and are still not well-understood.
How much BPA are we typically exposed to?
Authors noted that, among all studies reviewed, there has been significant variation in the levels of BPA found in identical food products—even those produced in the same batch. This calls into question studies that aim to test concentrations of BPA in human tissues.
A study, published in The Lancet in 2020, came to an even more worrying conclusion: that the studies used by regulatory agencies, like the FDA, had flaws that have led to major underestimates of exposure levels.
Past studies have largely relied on an indirect measurement method for BPA metabolites collected from humans, using an enzyme solution to transform metabolites back in a whole form of BPA. With a cohort of 29 pregnant women, researchers used two methods to test concentrations of BPA: the indirect method, and a direct method to measure the BPA metabolites themselves.
Using the direct method, they found that BPA concentrations were roughly 44 times higher than the average for US adults last reported by the National Health and Nutrition Examination Survey. In comparison, the indirect method indicated that BPA levels were 19 times lower than that average. Researchers subsequently confirmed this disparity after conducting a similar test on five men and five non-pregnant women.
Researchers concluded that the findings highlight the need for a reassessment from regulatory bodies.
Tips to avoid BPA
In the meantime, there are some small actions you can take to lower your BPA exposure. Brent Bauer, MD, of the Mayo Clinic, advises using products labeled “BPA-free” and bear in mind that recycled products with codes 3 or 7 may contain BPA. Another good starting point is to cut down on canned products as much as possible, and use glass or stainless steel containers for food and beverages. You should also avoid putting polycarbonate plastics in the microwave or dishwasher because the heat may allow BPA to transfer into foods.
Learn more here about other potentially harmful household items lurking in plain sight.