You have probably seen the letters BPA on baby products that advertise they are BPA-free. But, what is BPA, are baby products the only things to worry about, and what can we all do to avoid BPA?
What is BPA?
BPA stands for bisphenol A. It is a synthetic, organic compound created in 1891 by Russian chemist Aleksandr P. Dianin. It is used as an additive to polycarbonate plastics to make them stronger while remaining clear. It is also used to make epoxy resins.
BPA is a synthetic estrogen which means it mimics estrogen in the human body and can disrupt normal hormone behavior (making it an endocrine disruptor along with chemicals like DDT, Phthalates, and PCBs). When BPA was first found to be estrogenic in 1938 this was very exciting news as it was hoped that BPA could be used in pharmaceuticals. BPA probably would have become a frequently used medicine for women if another compound wouldn’t have been discovered around the same time with even more estrogenic properties: DES. Oh the irony[1. DES stands for Diethylstilbestrol. This drug was given to women throughout the 40s and 50s and was found to be a powerful teratogen (a chemical that causes fetal abnormalities) and to cause reproductive problems and cancers in children born from mothers prescribed it during pregnancy.].
Is BPA Dangerous?
I try to keep my posts on What Every Parent Should Know to the point and avoid any political or “consipiracy” type slant but they really make it hard! The fact is, industry, scientists, and government organizations have had evidence of the dangers of BPA for decades and are only in the past 8 years made any progress toward phasing it out. When you look at the history of BPA it is just infuriating that the FDA announced in Jaunary of 2010 that there might be “some concerns” about BPA. JANUARY OF 2010!! Let’s look at some of the dangers of BPA and pay special attention to the dates of these studies.
BPA and Prostrate Cancer
One of the first studies to show toxic effects of BPA was published in 1997 and repeated by several subsequent studies.
“Our findings show for the first time that fetal exposure to environmentally relevant parts-per-billion (ppb) doses of bisphenol A, in the range currently being consumed by people, can alter the adult reproductive system in mice.[2. Relative Binding Affinity-Serum Modified Access (RBA-SMA) Assay Predicts the Relative In Vivo Bioactivity of the Xenoestrogens Bisphenol A and Octylphenol Susan C. Nagel, Frederick S. vom Saal, Kristina A. Thayer, Minati G. Dhar, Michael Boechler and Wade V. Welshons Environmental Health Perspectives, Vol. 105, No. 1 (Jan., 1997), pp. 70-76]”
“An important and controversial health concern is whether low-dose exposures to hormonally active environmental estrogens, such as bisphenol A, can promote human diseases, including prostate cancer. Here, we show that transient developmental exposure of rats to low, environmentally relevant doses of bisphenol A or estradiol increases prostate gland susceptibility to adult-onset precancerous lesions and hormonal carcinogenesis. We found permanent alterations in the DNA methylation patterns of multiple cell signaling genes, suggesting an epigenetic basis for estrogen imprinting[3. Timms, B.; Howdeshell, K.; Barton, L.; Bradley, S.; Richter, C.; Vom Saal, F. (2005). “Estrogenic chemicals in plastic and oral contraceptives disrupt development of the fetal mouse prostate and urethra”. Proceedings of the National Academy of Sciences of the United States of America 102 (19): 7014–7019].”
BPA and Neuroblastoma Cancer
BPA has been shown to greatly increase the development of neuroblastoma tumors (in vitro means “in glass” referring to an experiment on cultured cells where in vivo means “in life” and refers to experiments on living organisms – in this case mice);
“In vitro, the BPA group had 20% higher number of viable cells, 70% higher proliferation index (both P < .01), and higher expression of cyclin-dependent kinase 4 and cyclin D1 than the nontreated group. In vivo, the BPA group had over 50% higher gross tumor volume, tumor weight, microvessel density, proliferating cell nuclear antigen (P < .05 or .01), and higher vascular endothelial growth factor protein expression than the mock control group. Both in vitro and in vivo BPA effects were comparable with those by E2[4. Growth-promoting effect of bisphenol A on neuroblastoma in vitro and in vivo Journal of Pediatric Surgery, Volume 44, Issue 4, Pages 672-680 H. Zhu, X. Xiao, J. Zheng, S. Zheng, K. Dong, Y. Yu].”
BPA and Breast Cancer
Low dose BPA exposure can increase breast cancer rates in adults and to fetuses. In fact the research shows that increased risk of breast cancer beings in the womb.
“This indicates that breast cancer risk can be affected by endocrine disruption not only in the adult but already in utero. Evidence from animal models is accumulating that perinatal exposure to environmentally relevant, low doses of a related compound, bisphenol A (BPA), alters breast development and increases breast cancer risk[5. Brisken, C. (2008). “Endocrine Disruptors and Breast Cancer“. CHIMIA International Journal for Chemistry 62: 406–409].”
“‘Hence, both animal experiments and epidemiological data strengthen the hypothesis that foetal exposure to xenooestrogens may be an underlying cause of the increased incidence of breast cancer observed over the last 50 years[6. Soto, A.; Vandenberg, L.; Maffini, M.; Sonnenschein, C. (2008). “Does breast cancer start in the womb?”. Basic & clinical pharmacology & toxicology 102 (2): 125–133].”
BPA and Brain Development and Behavior
BPA affected maternal behavior of mice;
“Dams [mother mice] exposed to BPA either as fetuses or in adulthood spent less time nursing their pups and more time out of the nest compared with the control group…The changes seen in maternal behavior may be the result of a direct effect of BPA on the neuroendocrine substrates underlying the initiation of maternal behavior[7. Paola Palanza, Kembra L. Howdeshell, Stefano Parmigiani, and Frederick S. vom Saal. Exposure to a Low Dose of Bisphenol A during Fetal Life or in Adulthood Alters Maternal Behavior in Mice Environmental Health Perspectives Supplements Volume 110, Number S3, June 2002].”
It also can effect memory and mood as shown in this primate study;
“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[8. Leranth C, Hajszan T, Szigeti-Buck K, Bober J, Maclusky NJ (September 2008). “Bisphenol A prevents the synaptogenic response to estradiol in hippocampus and prefrontal cortex of ovariectomized nonhuman primates”. Proc. Natl. Acad. Sci. U.S.A. 105 (37): 14187].”
BPA exposure has even been linked to schizophrenia.
BPA and the Dopaminergic System
The dopaminergic system is the reward system in our brains. Defects in this system can lead to addictions, attention disorders, and problems with impulse control. BPA disrupts this system;
“Endocrine disrupters such as Bisphenol A, mimic estrogenic activity and impact various dopaminergic processes to enhance mesolimbic dopamine activity resulting in hyperactivity, attention deficits, and a heightened sensitivity to drugs of abuse[9. Jones, D.; Miller, G. (2008). “The effects of environmental neurotoxicants on the dopaminergic system: A possible role in drug addiction“. Biochemical pharmacology 76 (5): 569–581].”
Other Health Effects
- BPA can increase susceptibility to obesity.
- BPA disrupts thyroid function.
- BPA exposure causes sexual dysfunction in men and in women.
“Higher urinary BPA concentrations were associatedwith cardiovascular diagnoses in age-, sex-, and fully adjustedmodels (OR per 1-SD increase in BPA concentration, 1.39; 95%confidence interval [CI], 1.18-1.63; P = .001 withfull adjustment). Higher BPA concentrations were also associatedwith diabetes (OR per 1-SD increase in BPA concentration, 1.39;95% confidence interval [CI], 1.21-1.60; P < .001)but not with other studied common diseases. In addition, higherBPA concentrations were associated with clinically abnormalconcentrations of the liver enzymes -glutamyltransferase (ORper 1-SD increase in BPA concentration, 1.29; 95% CI, 1.14-1.46;P < .001) and alkaline phosphatase (OR per 1-SDincrease in BPA concentration, 1.48; 95% CI, 1.18-1.85; P = .002)[10. Lang IA, Galloway TS, Scarlett A, Henley WE, Depledge M, Wallace RB, Melzer D (2008). “Association of Urinary Bisphenol A Concentration With Medical Disorders and Laboratory Abnormalities in Adults”. JAMA 300 (300): 1303].”
But I’m Breastfeeding so, this doesn’t matter to me, right?
That being said, exposure to BPA is much more ubiquitous than just baby feeding sources.
- Pizza boxes made of recycled cardboard
- Recycled paper
- Credit card receipts at the gas station and your local restaurant (thermal paper)
- Wine and Beer (fermented in BPA-resin lined vats)
- Pop (soda) cans
- Dental sealants
- Canned foods which are lined with BPA
- Of all foods tested, chicken soup, infant formula, and ravioli had BPA levels of highest concern. Just one to three servings of foods with these concentrations could expose a woman or child to BPA at levels that caused serious adverse effects in animal tests.
- For 1 in 10 cans of all food tested, and 1 in 3 cans of infant formula, a single serving contained enough BPA to expose a woman or infant to BPA levels more than 200 times the government’s traditional safe level of exposure for industrial chemicals. The government typically mandates a 1,000- to 3,000-fold margin of safety between human exposures and levels found to harm lab animals, but these servings contained levels of BPA less than 5 times lower than doses that harmed lab animals[11. http://www.ewg.org/reports/bisphenola].
What Can You Do?
- Use only powdered formula
- Use glass bottle, dishes, etc. Particularly for eating and anything that will be heated or washed with a detergent which can increase the leaching of BPA.
- Find BPA free water bottles. Using reusable water bottles and not plastic is good but many aluminum bottles are lined with BPA.
- Know your plastics by the Resin Code Identification (table adapted from Wikipedia). Avoid those in red (added by me):
Image Abbreviation Polymer name Uses PETE or PET Polyethylene terephthalate Polyester fibres, thermoformed sheet, strapping, and soft drink bottles(See also: Recycling of PET bottles) HDPE High density polyethylene Bottles, grocery bags, milk jugs, recycling bins, agricultural pipe, base cups, car stops, playground equipment, and plastic lumber PVC or V Polyvinyl chloride Pipe, fencing, and non-food bottles LDPE Low density polyethylene Plastic bags, 6 pack rings, various containers, dispensing bottles, wash bottles, tubing, and various molded laboratory equipment PP Polypropylene Auto parts, industrial fibers, food containers, and dishware PS Polystyrene Desk accessories, cafeteria trays, plastic utensils, toys, video cassettes and cases, and insulation board and other expanded polystyrene products (e.g., Styrofoam) OTHER or O Other plastics, including acrylic, acrylonitrile butadiene styrene, fiberglass, nylon, polycarbonate, and polylactic acid Bottles, plastic lumber applications. This is the “other” category so it may contain BPA but items listed as BPA-free may also have 7s.