Thursday, November 10, 2011

Other Toxic Substances - BPA: What You and Your Patients Need to Know About Bisphenol A

In June of this year, the American Medical Association formally recognized BPA as an endocrine-disrupting agent.
Physicians can play an important role in educating their patients about this pervasive environmental contaminant. The first steps are to understand the potential health risks of BPA and how to limit those risks through simple lifestyle changes.

BPA has been shown to leach from products that contain it, such as food cans, into the foodstuffs stored in the container.1,2 When the food is then consumed, BPA enters the body through the digestive tract.

BPA is used in the production of polycarbonate plastics and epoxy resins. Many consumer products, such as some reusable water bottles, baby bottles, toys, cell phones, and DVDs, contain BPA. BPA is also found in the inner linings of metal food cans.1 The epoxy lining protects the metal can from rust and corrosion which may taint the food. It is present in various medical devices as well, including incubators, blood oxygenators, and dialysis machines. Given its wide uses, BPA ranks among the highest volume chemicals manufactured worldwide.

A 2007 survey by the Centers for Disease Control found that approximately 92% of Americans have detectable levels of BPA in their bodies.3 The survey is considered representative of the United States population even though it included only people older than six years old. It is notable, however, that the children (ages 6-11 years) in this study displayed the highest levels of BPA of all populations investigated. BPA has been found in placental tissue and fetal blood as well, indicating that fetuses are being exposed as a result of maternal exposure.4

While most health studies regarding exposure to BPA are done in laboratory animals, the few human epidemiological studies reveal a relationship between BPA exposure and polycystic ovary syndrome, repeated miscarriage, and heart disease.6-8

Likely human health effects that have been vetted through these review panels include advanced puberty in females14, 15 , effects on the brain and behavior15, 16, mammary gland and prostate abnormalities, and reproductive effects in males and females.Beyond the immediate developmental effects of BPA exposure in utero, evidence is beginning elucidate long-term effects of early-life exposure to BPA, potentially through the modification of epigenetic programming via altered DNA methylation.16, 17 One study suggests that such detrimental modifications may be counteracted by maternal nutrient supplementation.18 Nevertheless, these changes may result in alterations that are passed on transgenerationally, resulting in adverse health effects in subsequent generations who, themselves, may not have been directly exposed to BPA.17, 19
For more information on how to reduce your exposure to BPA
Coca-Cola Shareholders Spurred by Conscience or Profit?

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