BPA Myths and Facts
From the November 2011 Breast Cancer Fund report, BPA in Thanksgiving Canned Food.
MYTH: These are just small amounts of BPA that don’t really matter.
FACT: Increasingly, scientists are learning that low doses of some chemicals can disrupt hormone systems, especially when exposures occur early in life—a critical window of development.
People are not exposed to one chemical at a time, but rather to multiple chemicals throughout their lives. Studies have shown that exposures to multiple chemicals can either act additively (in other words, the combination is like a higher dose of either chemical)1,2 or synergistically (the combination greatly increases the effects of either chemical).3,4 In addition, endocrine disruptors like BPA can interact with the body's natural hormone levels,5 so even a small exposure can increase total hormonal activity.
Several studies have shown that BPA exerts effects similar to those of diethylstilbestrol, or DES, which was prescribed to millions of pregnant women between 1947 and 1970.6 It took researchers many years to discover DES's devastating effects on women's risk of various cancers, including breast cancer. And now we know that the daughters of women who took DES during pregnancy have an increased chance of developing breast cancer.7 We don't want to wait and learn that the next generation of children exposed to regular doses of BPA also has an increased risk of cancer.
It's difficult to study these low-dose hormonal effects in human health studies for several reasons: (1) it may take years or decades for the effects to unfold; (2) since the chemicals are common, we can't compare people who are exposed with people who aren't exposed the way we would when we test a drug; (3) in everyday life, we're exposed to many different chemicals, and the effects of these multiple chemicals are difficult to tease out from the effects of a single chemical; (4) it would be unethical to purposefully expose humans to chemicals of concern to measure the health effects of those chemicals.
MYTH: The amounts of BPA in canned foods are lower than those found in polycarbonate bottles (including some baby bottles and water bottles).
FACT: The amounts of BPA we found in canned foods tested for this report were higher than those reported for water bottles held at room temperature.1 Levels in water bottles only approached those we found in cans when the bottles were heated.
MYTH: BPA from cans is so quickly metabolized in the body that it cannot affect health.
FACT: A number of studies have sought to understand how humans metabolize BPA. Even though blood levels may be much lower than urine levels, studies looking at urine levels have found associations with several clinical disorders in humans,8 including miscarriages;9 obesity; cardiovascular and metabolic disorders;10 male reproductive dysfunction;11 and behavioral issues in girls.12 The human data on these disorders are entirely consistent with the data that associate BPA exposure in animals with the same kinds of negative health effects.
MYTH: Alternatives to BPA are only available for the rich who can afford and have access to fresh food.
FACT: If we get BPA out of food packaging, everyone will benefit. Meanwhile, there are some steps people can take to reduce their BPA exposure at home that don't cost much more. Packaging alternatives like Tetra Pak cartons and frozen vegetables do not rely on plastics that contain BPA. Dry pasta and beans are actually cheaper than canned. But there's only so much any of us—regardless of income—can do to avoid canned food, as it is used in schools, hospitals, cafeterias and restaurants. We can't fully protect ourselves without market and policy change. Companies and legislators need to hear from us that we want BPA-free food packaging, and that all of us, regardless of income, should be protected.
MYTH: Advocacy groups are the only ones concerned about BPA.
FACT: The EU has banned BPA from baby bottles, as have Canada, China and a number of other countries. Here in the United States, 11 states have restricted the use of BPA in infant feeding products. These nations and states are acting on the evidence from more than 200 laboratory studies that raise concerns about the negative health effects of BPA.
The Endocrine Society, the world's oldest, largest and most active organization devoted to research on hormones, issued its first-ever scientific statement on BPA in 2009, saying that BPA can interfere with our hormone system even at exquisitely low doses and that this is especially true for children exposed during critical windows of development (including before birth). The statement's authors said that while they still have questions about BPA, there's clearly enough evidence to begin reducing exposures; the statement also said that the Endocrine Society should "actively engage in lobbying for regulation seeking to decrease human exposure" to BPA.13 More recently, the American Medical Association recognized BPA as an endocrine-disrupting agent, and urged that products containing the chemical be identified.14 The AMA supports industry efforts to stop producing baby bottles and sippy cups made with BPA.
MYTH: BPA is only found in conventional canned foods. Organic canned foods are free of BPA.
FACT: Many consumers think that if a product is organic, it must be safe. But the organic label only tells us about the food in the can. It doesn't tell consumers anything about the chemicals lining the can, which can get into the food and then into people. In fact, a September 2011 report by the Breast Cancer Fund documents the presence of BPA in organic canned food marketed to children. Consumers have a right to know if the foods they buy are made with organic ingredients, but they also have a right to trust that the packaging is free of harmful chemicals.
- Ramamoorthy K, Wang F, Chen IC, et al. (1998). Potency of combined estrogenic pesticides: Synergism between synthetic estrogens? Science, 275:405-406.
- Foster WG, Younglai EV, Boutross-Tadross O, et al. (2004). Mammary gland morphology in Sprague-Dawley rats following treatment with an organochlorine mixture in utero and neonatal genistein. Toxicol Sci, 77: 91-100.
- Arnold SF, Klotz DM, Collins BM, et al. (1996). Synergistic activation of estrogen receptor with combinations of environmental chemicals. Science, 272:1489-1492.
- Xie L. Thrippleton K, Irwin MA, et al. (2005). Evaluation of estrogenic activities of aquatic herbicides and surfactants using a rainbow trout vitellogenin assay. Toxicol Sci, 87:391-398.
- Rajapakse N, Silva E, Kortenkamp A (2002). Combining xenoestrogens at levels below individual no-observed-effect concentrations dramatically enhances steroid hormone action. Environ Health Perspect, 110:917-921.
- Giusti RM, Iwamoto K, Hatch EE (1995). Diethylstilbestrol revisited: a review of the long-term health effects. Ann Int Med, 122, 778–788.
- Li S, Hursting SD, Davis BJ, et al. (2003). Environmental exposure, DNA methylation, and gene regulation: Lessons from diethylstilbestrol-induced cancers. Annals NY Acad Sci, 983:161-169.
- Lang IA, Galloway TS, Scarlett A (2009). Association of urinary bisphenol A concentrations with medical disorders and laboratory abnormalities in adults. JAMA, 300:1303-1310.
- Sugiura-Ogasawara M, Ozaki Y, Sonta S, Makino T, Suzumori K (2005). Exposure to bisphenol A is associated with recurrent miscarriage. Human Reproduction 20: 2325-2329.
- Melzer D, Rice NE, Lewis C, Henley WE, Galloway TS (2010). Association of urinary bisphenol A concentration with heart disease: Evidence from NHANES 2003/6. PLoS ONE, 5: e8673.
- Galloway T, Cipelli R, Guralnik J, Ferrucci L, Bandinelli S, et al. (2010). Daily Bisphenol A Excretion and Associations with Sex Hormone Concentrations: Results from the InCHIANTI Adult Population Study. Environ Health Perspect, 118(11): doi:10.1289/ehp.1002367.
- Braun JM, Kalkbrenner AE, Calafat AM, et al. (2011). Impact of early-life bisphenol A exposure on behavior and executive function in children. Pediatrics. Advance Access Publication: http://pediatrics.aappublications.org/content/early/2011/10/20/peds.2011-1335.abstract
- Diamanti-Kandarakis E, et al. (2009). Endocrine-Disrupting Chemicals: An Endocrine Society Scientific Statement. Endocr Rev, 30:293-342.
- Dolan PL (2011). AMA supports tighter restrictions on products containing BPA. AMA News. http://www.ama-assn.org/amednews/2011/07/04/prsg0704.htm.