About Bisphenols: Artificial Chemicals Found in Plastic
Bisphenols, commonly used in plastic products, are considered obesogens, which are chemicals that affect the metabolism and disrupt the body’s natural regulation processes for appetite, satiety and fat storage.
But research shows that BPS (bisphenol-S) and BPF (bisphenol-F), which are increasingly substituted for the high-profile endocrine disruptor BPA (bisphenol-A), may not be any safer than BPA.
BPA, which mimics estrogen in the body, has been linked to youth and adult obesity as well as fertility problems, heart disease and other health issues, according to a 2012 study published in the Journal of the American Medical Association (JAMA).
But does switching to BPA free replacement chemicals actually make a difference?
BPA vs. BPS and BPF
You don’t need to be a scientist to figure out that bisphenol-S and bisphenol-F sound awfully similar to bisphenol-A.
“They’re extremely similar. It’s hard to say in layman’s terms, but it’s just a replacement of a couple of molecules,” said Melanie Jacobson, a lead study author and a research scientist at New York University’s Langone Health.
Turns out those “BPA Free” labels intended to reassure consumers may not be, as Jacobson explained, entirely “transparent.”
“When a plastic container says ‘BPA Free,’ it’s more than likely a sign that it has BPS or BPF,” she said.
Though some companies, she added, are using a natural can liner called oleoresin, she hasn’t seen any clear labels to differentiate those cans from the ones containing BPS or BPF.
According to an Environmental Working Group article, oleoresin is a natural mixture of an oil and a resin derived from a plant. The mixture, which may be a safer alternative, likely hasn’t caught on because of higher cost.
Measuring Bisphenols and Obesity in U.S. Children and Adolescents
Currently, one in five American youth ages 6 to 19 has obesity, a rate that has tripled since the 1970s. Obese youth are at greater risk for a host of serious physical and psychological problems including high blood pressure, high cholesterol, type 2 diabetes, asthma, joint problems, gallstones, anxiety, depression and low self-esteem.
The study, published in the Journal of the Endocrine Society in July 2019, found an association between obesity and the amount of BPF and BPS in the urine of children and adolescents ages 6 to 19. The researchers used various measures of obesity independent of other factors such as age, sex, race/ethnicity, parental education and physical activity.
BPA was detected in nearly all urine samples (97%), while 88% of samples contained BPS and 55% contained BPF. Jacobson attributed the greater prevalence of BPA to the fact that it’s been in use longer.
While this study didn’t find an association between BPA and youth obesity, an earlier study published in JAMA in 2012 based on data from 2003 to 2008 found a significant association. Part of the reason for that, Jacobson said, could be that the amount of BPA in youth urine was much higher back then. The transition to BPS and BPF is a more recent development.
As BPA levels are going down, BPS and BPF levels are going up.
Jacobson stressed that these are preliminary results from a cross-sectional study, meaning that it only looked at one moment in time and that further investigation is needed. A longitudinal study would yield more conclusive data by tracking the relationship between chemical exposure and youth weight gain over a period of time.
It’s an initial step, although there is potentially cause for concern, she said.
Sources of BPA, BPS and BPF Exposure
Potential sources of BPA, BPS and BPF exposure include baby bottles, sippy cups, pacifiers, children’s toys, household electronics, CDs and DVDs, eyeglass lenses, sports equipment, toiletries and dental sealants.
However, it’s dietary exposure — the food container issue — that’s most concerning, according to Lori Hoepner, an assistant professor of environmental and occupational health sciences at SUNY Downstate Health Sciences University School of Public Health.
How to Limit Exposure to BPA, BPS and BPF
Obese youth are at greater risk for a host of serious physical and psychological problems including high blood pressure, high cholesterol, type 2 diabetes, asthma, joint problems, gallstones, anxiety, depression and low self-esteem.
To be on the safe side, Jacobson advised parents to reduce reliance on canned goods and plastic food packaging wherever possible. In particular, she urged parents not to heat plastic, which can increase the likelihood of chemicals leaching into food. When it comes to receipts, she said, choose electronic (emailed) receipts whenever possible.
Pregnant women and women considering conceiving a child are also advised to limit their exposure to BPA, BPS and BPF, which are known to cross the placental barrier. Although we don’t have enough information yet about how the chemicals might impact the fetus, they could potentially predispose newborns to childhood obesity, according to Hoepner, author of a recently-published review in the journal Environmental Research of prenatal BPA exposures and childhood obesity research.
“BPA, BPS and BPF could have bad outcomes, so why increase risk? Do the best that you can to reduce risk in ways that you can control,” she said.
The Environmental Working Group has a list of tips for reducing exposure to BPA, which would also apply to reduce exposure to BPS and BPF.
Footnotes
1. Trasande L, Attina TM, Blustein J. Association Between Urinary Bisphenol A Concentration and Obesity Prevalence in Children and Adolescents.JAMA.2012;308(11):1113–1121. doi:https://doi.org/10.1001/2012.jama.11461
2. Melanie H Jacobson, Miriam Woodward, Wei Bao, Buyun Liu, Leonardo Trasande, Urinary Bisphenols and Obesity Prevalence Among U.S. Children and Adolescents,Journal of the Endocrine Society, Volume 3, Issue 9, September 2019, Pages 1715–1726,https://doi.org/10.1210/js.2019-00201
3. Lori A. Hoepner, Bisphenol a: A narrative review of prenatal exposure effects on adipogenesis and childhood obesity via peroxisome proliferator-activated receptor gamma, Environmental Research, Volume 173, 2019, Pages 54-68, ISSN 0013-9351, https://doi.org/10.1016/j.envres.2019.03.012.