When consumer outcry got loud enough and states started their own bans, manufacturers stopped using bisphenol-A (BPA) in some baby products. In 2012, the FDA took limited action – no BPA in baby bottles, sippy cups and infant formula cans. Thus, the “BPA-free” craze was born! Unfortunately, products that boast “BPA-free” may contain bisphenol-S (BPS), BPA’s less studied chemical cousin.
Bisphenols, such as BPA and BPS, are found in polycarbonate plastics in products like sports bottles (the hard, transparent stuff), canned food and beverage linings, thermal receipt paper, and many others. Both BPA and BPS have been linked to adverse health effects in recent studies. In particular, they are known endocrine disrupting compounds, that is, they alter hormones and disrupt bodily systems at very low concentrations. Numerous studies have found that prenatal exposure to such chemicals could be especially harmful, suggesting that pregnant mothers should limit their exposure to bisphenols.
BPA has been found in the urine of 93% of people tested, and BPS in 97% of those tested. Basically, we’re all exposed to these highly pervasive chemicals. So what can we do to reduce our exposure to these hormone-altering chemicals?
Turns out that choosing products labeled BPA-free is not a solution. As the authors of a new research study warn,
“BPA-free products are not necessarily safe and support a societal push to remove all structurally similar bisphenol…compounds…from consumer goods.”
In other words, let’s not trade one potentially harmful chemical (BPA) for one that’s structurally similar (BPS) and likely to pose similar risks. Looking at whole families or classes of chemicals is a better way of regulating their use.
A controversial backstory: BPA linked to lower sperm production and adverse effects on heart health and blood pressure, but approved for use in food contact materials
As reported in Environmental Health News “scientists previously found BPA exposure impacts mice testis size and sperm development and prostate growth. But what [scientists from Washington State University] did was different – they found a possible reason why these things happen: changes to the stem cells, which are vital for male reproduction. Lead researcher and geneticist Patricia Hunt says exposure to estrogens (and remember, BPA mimics estrogen) “is not simply affecting sperm being produced now, but impacting the stem cell population, and that will affect sperm produced throughout the lifetime.”
Two recent studies show BPA also affects heart health. Medical researchers in South Korea compared effects of drinking a beverage from BPA-lined cans with drinking the same beverage from glass bottles. There was a small increase in systolic blood pressure when people drank from BPA-lined cans but not when they drank from glass. (Heart rate was not affected by BPA.) Dr. Donald Lloyd-Jones at Northwestern University was not involved in the study but commented,
“while [the] difference sounds small … when you translate that difference to a large population it could have real meaning in terms of heart attacks, strokes and heart failure for people who drink such beverages frequently.”
In the other study, scientists at the University of Cincinnati looked at the effects of long-term, chronic exposure to BPA on mice. Mice were exposed to varying levels of BPA with and without a drug called isoproterenol. The drug mimics some of the damaging effects of a heart attack. Dr. Scott Belcher says
“the results of this study find heart and blood pressure effects in male and female mice, with females seemingly at greater risk for harm … For female mice exposed to BPA there was a severe increase in the sensitivity to cardiotoxic damage. This effect was especially striking because females are typically protected.”
Despite all this research, Dr. Rolf Halden notes,
“the health risks of BPA are fiercely debated and, after more than 70 years of study, are still not fully understood. The stakes are high because exposure is ubiquitous and BPA-containing products are a multi-billion-dollar enterprise”.
The Food and Drug Administration (FDA) is also ambiguous about its stance on BPA. On the one hand, the FDA concedes that “small, measurable amounts of [food] packaging materials may migrate into food and can be consumed with it.” On the other hand, it maintains that BPA is safe at current levels in food and in food packaging.
The American Chemistry Council (ACC), a trade association for chemical manufacturers, tried to have BPA removed from California’s Prop 65. Despite industry pressure, California courts upheld the BPA health warning.
A risky replacement: BPS linked to heart arrhythmias; hormone disruption; abnormal brain development and hyperactivity
University of Cincinnati researcher Dr. Hong-Sheng Wang reports BPS “may have acute cardiac toxicity similar to that of BPA”. In a 2014 study, exposure to BPS led to heart rhythm abnormalities in female rat hearts under stress condition. The effect was not seen in males rats.
As reported in Science Daily, a University of Texas Medical Branch (UTMB) study found that “BPS disrupts cellular responses to the hormone estrogen, changing patterns of cell growth and death and hormone release”. UTMB professor Cheryl Watson says, “our studies show that BPS is active at…levels likely to be produced by BPS leaching from containers into their contents.”
Scientists at the University of Calgary exposed zebrafish embryos to BPA and BPS. (Zebrafish are a good model for studying human brain development.) The exposures were so low the researchers didn’t expect to see any effects. What they found surprised them. The Washington Post reports both BPA and BPS were shown to disrupt normal brain-cell growth and were linked to hyperactivity.
Scientists from the Michigan, Calgary and Mailman SPH studies emphasized the need for regulation of prenatal exposure to these chemicals because “exposure during pregnancy is likely the most sensitive period for brain development.”
Consumers are understandably confused; one minute BPA-free is the answer, the next it’s not. So if BPA-free is not the solution, what can one do? I choose to err on the side of caution and avoid as much as possible products that might contain bisphenols.
I don’t take sales receipts unless necessary; I opt for electronic ATM receipts and boarding passes; I don’t put plastics in the microwave or dishwasher, and no harsh detergents when handwashing them. When I do buy plastic, I look for recycling codes 1, 2, 4 and 5, which are considered safer. My plastic sports bottles have been replaced by glass and stainless steel (with silicone caps). I’m cutting down on canned foods, and buying fresh and frozen, and food in glass containers instead. Last but not least, if I had young children, they’d be drinking from glass or stainless steel bottles and sippy cups, and I wouldn’t let them handle receipts. Let the buyer beware.