Concerns about Bisphenol A and How You Can Protect Yourself

Bisphenol A (BPA) is a chemical currently used to manufacture hard, light-weight plastic water bottles that have #7 recycle designation or “PC” for polycarbonate on the bottom. BPA is also used in baby bottles, as well as epoxy linings of metal food cans, including canned infant formula. Nearly six billion pounds of BPA is produced annually. The BPA molecules link to form polymers which are unstable, break-off, and allow the BPA to leach into the water and food that comes in contact with the plastic. New research indicates that BPA acts like a synthetic estrogen, also called a xenoestrogen (external, non-human made estrogen) that acts as an endocrine disrupting chemical (1).

For a long-time the plastics manufacturers have assured the government and the public that BPA is safe. However, studies conducted over the past 20 years now show it’s not only an ubiquitous pollutant in the human body, contaminating nearly 93% of the population, but also a potent developmental toxin at very low doses (2). The Environmental Working Group (EWG) has put together a timeline about BPA. Here are the highlights:
1891: BPA discovered.
1930s: First evidence of toxicity. The chemical industry begins to use BPA to manufacture a hard plastic called polycarbonate, and to make epoxy resins used as linings for metal food cans and a variety of other products. Although BPA leaches out of plastic long after its manufacture, the material is used in consumer products with no requirement that companies prove it is safe.
1976: First law to regulate industrial chemicals fails to establish safety for BPA which is one of 62,000 chemicals “grandfathered” in and presumed safe by the Environmental Protection Agency.
Late 1980s through 1990s: First BPA safety standard at odds with first low-dose BPA studies.
2003-2006: First serious government evaluation of BPA low-dose toxicity led by industry consultant.
2007: Industry influence on BPA science is revealed. Agency fires contractor. Government panel ignores low-dose BPA toxicity in favor of industry studies, BPA experts warn of health risks.
Late 2007-Early 2008: FDA and infant formula manufacturers’ positions on safety of BPA for babies come under fire, Congress investigates.
2008: Government finds BPA poses risks to humans, Wal-Mart and other retailers pull BPA products from shelves. Industry fights California effort to ban BPA from kids products. FDA poised to ignore dozens of laboratory studies and declare BPA exposures to baby “safe”. 2009: Over 20 states introduce bills to reduce children’s exposure to BPA. Is 2009 the year of action? (2)
Here are three research studies that validate three key steps in understanding the concerns about BPA. First research tested the hypothesis that “bioactive BPA was released from polycarbonate bottles used for consumption of water and other beverages. . .[and] evaluated whether BPA migrated into water stored in new or used high-quality polycarbonate bottles used by consumers. . . .BPA was found to migrate from polycarbonate water bottles at rates ranging from 0.20 nanograms/hour to 0.79 nanogram/hour. At room temperature the migration of BPA was independent of whether or not the bottle had been previously used. Exposure to boiling water (100 °C) increased the rate of BPA migration by up to 55-fold” (3).
Second, BPA enters the body & is excreted by kidneys. A study published in 2009 involving 77 Harvard College students “examined the association between the use of polycarbonate beverage containers for one week and urinary BPA concentrations.” The authors concluded, “One week of polycarbonate bottles use increased urinary BPA concentrations by 69%. Regular consumption of cold beverages from polycarbonate bottles is associated with a substantial increase in urinary BPA concentrations irrespective of exposure to BPA from other sources”(4).

BPA has significant affects on non-human primates. Researchers . . . examined the influence of continuous BPA administration, at a daily dose equal to the current U.S. Environmental Protection Agency’s reference safe daily limit, on estradiol-induced spine synapse formation in the hippocampus and prefrontal cortex of a nonhuman primate [monkey] model. Our data indicate that even at this relatively low exposure level, BPA completely abolishes the synaptogenic response to estradiol. Because remodeling of spine synapses may play a critical role in cognition and mood, the ability of BPA to interfere with spine synapse formation has profound implications. This study is the first to demonstrate an adverse effect of BPA on the brain in a nonhuman primate model and further amplifies concerns about the widespread use of BPA in medical equipment, and in food preparation and storage (5).

For more information refer to the review article by Vandenberg et.al. (6) and the list of 525 articles (7).

Do you carry a plastic water bottle, either clear or colored? Check the bottom. Do you find a triangular recycle logo with the number “7” in the center and/or the letters “PC”? If so, that bottle contains BPA. To reduce your exposure:
* Avoid bottles and plastic containers that are made from polycarbonate.
* Carry water in stainless steel bottles
* Eat less canned food and more frozen or fresh food.
* Breastfeed your baby or use powdered formula instead of cans.
* Download “EWG’s Guide to Infant Formula and Baby Bottles: Guide to Baby-Safe
Bottles & Formula” and share it with someone you know who is pregnant or has a small infant (8).

References:
1. Hoffman, Matthew, “Pots, Pans, and Plastics: A Shopper’s Guide to Food Safety”, Web MD, March 6, 2009
2. Houlihan, J. et.al. “Timeline: From Invention to Phase-Out”, April 2008

3. Hoa HL et.al. “Bisphenol A is released from polycarbonate drinking bottles and mimics the neurotoxic actions of estrogen in developing cerebellar neurons”, 2008; 176(2):149-156
4. Carwile, JL, et. al. “Polycarbonate Bottle Use and Urinary Bisphenol A Concentrations”, 2009; Environmental Health Perspectives; 117(9)
5. Csaba, Leranth et.al. “Bisphenol A prevents the synaptogenic response to estradiol in hippocampus and prefrontal cortex of ovariectomized nonhuman primates”, 2008; Proceedings of the National Academy of Sciences; 105(37): 14187-14191.
6. Vandenberg, LN, et. al. “Human exposure to bisphenol A (BPA)” 2007; Reproductive Toxicology;24(2):139-77.
7. References and abstracts for 525 articles about BPA
8. “EWG’s Guide to Infant Formula and Baby Bottles: Guide to Baby-Safe Bottles & Formula”

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You may have heard of this chemical but not known exactly what it does to the human body.