More than 1 million pounds of bisphenol A, or BPA, are released into the environment each year, but scientists are beginning to find that it could take just a tiny amount to create strange and lasting health problems. Embedded in some plastics, as a protective lining inside most food and drink cans, and as a coating on cash-register receipts, BPA is in so many everyday products that it's inside of most of us, too.
Researchers have detected the industrial chemical in the blood and urine of most Americans; it even turns up in amniotic fluid and placentas, meaning fetuses are exposed before birth. Yet, in an increasing number of studies, BPA is being found to be a reproductive, developmental, and systemic toxicant. Much of the focus has been on the chemical's ability to interfere with levels of estrogen in the body, but scientists are discovering that its effects spread far beyond hormonal systems, resulting in health problems that are downright bizarre.
Here's how scientists say BPA could be affecting our bodies:
In 2013, French researchers published a study showing that daily low doses of BPA could be damaging tooth enamel. A research team from the Université Paris–Diderot found that within 30 days, newborn rats exposed to small amounts of BPA daily experienced molar incisor hypo-mineralization, a condition that causes hypersensitivity and increases the risk of developing cavities. Roughly 18 percent of children between the ages of 6 and 8 experience this unhealthy change that leads to white marks on teeth and brittle enamel.
The researchers note that children's teeth form in the first year of life—a period when human bodies are often most sensitive to BPA. According to study coauthor Sylvie Babajko, "Insofar as BPA has the same mechanism of action in rats as in men, it could also be a causal agent of MIH. Therefore, teeth could be used as early markers of exposure to endocrine disruptors acting in the same way as BPA and so could help in early detection of serious pathologies that would otherwise have occurred several years later."
A 2011 animal study published in the journal PLOS One found BPA overrode the female body's natural heartbeat signaling, causing arrhythmia—erratic beating that could cause sudden cardiac death. The chemical has long been believed to cause heart disease, and this study provided insight into how BPA impacts the heart.
Freaky Food Intolerance Problems
An October 2014 study published in the Federation of American Societies for Experimental Biology (FASEB) Journal found that mice exposed to BPA as pups (infant mice) until they were weaned demonstrated an exacerbated immune response to a new food protein. Continuing to eat the food protein resulted in chronic inflammation, which is an indication of a food intolerance that was not observed in animals who weren't exposed to BPA. Gerald Weissmann, MD, editor-in-chief of the FASEB Journal, responded to the study results, saying, "We may look back one day and see BPA exposure as one of the more important public health problems of our time."
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Low Sex Drive
A May 2013 study led by Chinese researchers and published in the journal Fertility and Sterility found chronic exposure to BPA leads to lower testosterone levels in men. BPA, which acts similarly to a synthetic form of estrogen, can throw off men's sex hormones levels, which can sink their sex drive. Earlier evidence came in 2010, when the results of a five-year study in humans confirmed that high levels of BPA in the urine correlated with low sperm counts and poor sperm quality. (It's one of these 11 sex-drive killers.)
Mysterious Spikes in Blood Pressure
While canned food is often to blame for spikes in BPA in your body, canned drinks, including soda and energy drinks, also pose a risk. December 2014 research published in the American Heart Association's journal Hypertension found that drinking just two canned beverages raises BPA concentrations in your body 1,600 percent and raises systolic blood pressure by 4.5 mm Hg.
"A 5-mm Hg increase in systolic blood pressure by drinking two canned beverages may cause clinically significant problems, particularly in patients with heart disease or hypertension," said Yun-Chul Hong, MD, PhD, study author and chair of the department of preventive medicine and director of the Environmental Health Center at Seoul National University College of Medicine in South Korea. (A 20-mm Hg increase in blood pressure doubles your risk of heart disease.)
Studies in the lab find that BPA has the ability to accelerate fat-cell differentiation, disrupt pancreatic functioning, and cause insulin resistance, leading to obesity problems. A recent Chinese study published in The Journal of Clinical Endocrinology & Metabolism found adults with the highest level of BPA were 50 percent more likely to be fatter, with a body mass index in the overweight or obese category. Study participants with high BPA levels were also 28 percent more likely to harbor dangerous abdominal fat.
"This human study, together with the previous studies that show relationships between BPA exposures and obesity or other metabolic endpoints, are concerning because they suggest that there are no 'safe' populations—even adults may be affected by low-level exposures to this chemical," BPA expert Laura N. Vandenberg, PhD, postdoctoral fellow of regenerative and developmental biology at Tufts University, told Rodale News when the study was released.
Disrupted Cancer Treatment
Research presented at the International Society of Endocrinology and the Endocrine Society 2014 meeting indicated that human cancer cells grow faster and respond less to an approved cancer-fighting drug when they've been exposed to various levels of BPA. "Routine exposures to common environmental chemicals like BPA appear to contribute to breast cancer cell progression and to diminish drug-treatment efficacy," says Gayathri Devi, PhD, of Duke University.
Devi explains that treatment ineffectiveness is worse for patients with inflammatory breast cancer, a rare but more aggressive form of cancer that has some of the lowest survival rates. "Cancer patients must understand there's a component in their daily lives that could influence their treatment outcome," Devi says.
The canned food of today could impact the health of your great-great grandchildren! A recent study published in the journal Endocrinology studied the trans-generational effects of BPA on mice. Compared to a mother mouse who ate BPA-free food, the who ate BPA-laced food gave birth to less social, more isolated pups. Some of the behavioral changes they observed in mice while studying the different generations exposed to BPA included symptoms associated with autism and attention-deficit hyperactivitiy disorder. Genetically speaking, BPA exposure changed how estrogen receptors switched on and off.
While consumer pressure has led to bans on BPA in baby bottles and canned baby formula manufactured in the U.S., the chemical is still used in things like polycarbonate water bottles, plastic utensils, and other food containers. France is taking a more hard-line approach, banning BPA in all food containers by July 2015. Still, the U.S. has made no such move to prevent what scientists consider dangerous, low-dose exposures.
• Avoid plastic food and drink containers—use food-grade stainless steel or glass instead. Beth Greer, author of Super Natural Home, suggests avoiding #7 plastic bottles made of BPA-laced polycarbonate."Those fabulous colorful hard plastic bottles may leach BPA as bottles age, are heated, or are exposed to acidic solutions," she notes. Instead, she recommends water bottles made of high-quality stainless steel, including those manufactured by Klean Kanteen and Earthlust.
• Say no to trivial receipts. Experiments show it transfers from the paper and through your skin. When you need a receipt, store it in an envelope, not in your wallet or in the bottom of your purse where you'll have repeated contact with it.
• Opt for fresh and/or frozen vegetables instead of canned.
• Be skeptical of BPA-free claims. A 2013 study found a common BPA replacement, BPS, also features hormone-disrupting qualities.
Filed Under: BPA AND PLASTIC
Published on: July 15, 2013