Photo (cc) by stevendepolo
Just when you thought it was safe to drink from your BPA-free water bottle, a slew of scientific studies makes it hard to swallow the idea that your replacement plastic bottle is harmless.
For years, we heard reports that estrogen-mimicking bisphenol-a (BPA) increased our risks of certain cancers, fertility reduction, birth defects and diabetes.
The U.S. Food and Drug Administration in 2012 banned BPA from baby bottles, sippy cups and, in 2013, from infant formula packaging — all practices already phased out by manufacturers.
While the FDA as late as November 2014 called BPA levels in other food containers and packaging safe, many manufacturers heeding consumer sensitivities churned out “BPA-free” bottles.
Many replaced BPA with BPS, or bisphenol-s, a similar chemical.
Recent scientific studies rebut claims that BPS is safe — and at least one researcher called for removal of all bisphenols from consumer products.
A University of Calgary study, published in the Proceedings of the National Academy of Sciences, found zebrafish embryos exposed to very low doses of BPA and BPS had altered brain development leading to hyperactivity.
The chemical exposure changed the timing when neurons were formed in the zebrafish brains.
“These findings are important because they support that the prenatal period is a particularly sensitive stage, and reveals previously unexplored avenues of research into how early exposure to chemicals may alter brain development,” Cassandra Kinch, a doctoral student and research leader at the university’s Cumming School of Medicine, told the university.
The findings add weight to other studies suggesting pregnant women should try to limit their exposure to items containing bisphenols, said Deborah Kurrasch, Ph.D., a Cumming researcher and corresponding author on the paper. The evidence also supports removing all bisphenols and structurally similar chemicals from consumer products, she said.
The American Chemistry Council, a trade group representing companies using chemicals, disagrees.
“The relevance of this limited study on zebrafish, as asserted by the authors, is not at all clear, and it would not be scientifically appropriate to draw any conclusions about human health based on this limited experiment,” said Steven Hentges, of the council’s Polycarbonate/BPA Global Group. “Many government bodies around the world have evaluated the scientific evidence on BPA and have clearly stated that BPA is safe as used in food contact materials.”
Hong-Sheng Wang, a pharmacologist at the University of Cincinnati, recently led a study that found the heart rates of female rats sped up and went into arrhythmias when exposed BPA and BPS. Male rats were not affected the same way, said the study published Feb. 26 in Environmental Health Perspectives. In people, Wang said, BPS might lead to heart damage or put those with pre-existing heart conditions or stressful lives at risk for heart disease.
French researchers exposed small pieces of tissue taken from developing mouse and human testes to BPA, BPS and bisphenol-F (BPF). All the chemicals lowered the production of testosterone in these tissues, and BPS proved to be a more potent testosterone-blocker than BPA.
The chemistry council says don’t worry about BPA, let alone BPS, based on FDA and other studies.
“Because of the way BPA is processed in the body, it is very unlikely that BPA could cause health effects at any realistic exposure level,” the council says.
The FDA did report that studies found that primates, including humans, of all ages effectively metabolize and excrete BPA much more rapidly and efficiently than rodents.
A Centers for Disease Control and Prevention study found detectable levels of BPA in 93 percent of 2,517 urine samples from people age 6 and older.
BPA can leach into food from the protective internal epoxy resin coatings of canned foods and from consumer products like polycarbonate tableware, food storage containers and water bottles, the National Institutes of Health says.
Other ways include cash register receipts, air, water and dust. Some dental sealants and composites may also contribute to BPA exposure, the NIH says.
To avoid BPA exposure, the NIH suggests:
- Don’t microwave polycarbonate plastic food containers. Polycarbonate is strong and durable, but over time it may break down from overuse at high temperatures.
- Plastic containers have recycle codes on the bottom. Some, but not all, plastics that are marked with recycle codes 3 or 7 may be made with BPA.
- Reduce your use of canned foods.
- When possible, opt for glass, porcelain or stainless steel containers, particularly for hot food or liquids.
If you’re buying a plastic water bottle, check the label. Some manufacturers show their products are made with neither BPA or BPS.
What’s your approach to plastics? Let us know in the comments section below or on our Facebook page.