Marc Joseph Nutrition - Blog

Environmental advocacy agency, Environment California (EC), just issued an interesting report titled, “Toxic Baby Bottles,” on the potential health risks of bisphenol-A released from common polycarbonate plastic baby bottles:

Press Release

Executive Summary

Report (PDF)

EC found that five of the leading plastic baby bottles leached bisphenol-A at levels greater than those shown to cause harm in several animal studies.

Bisphenol-A is an estrogen-mimicking chemical and a widespread environmental contaminant. From the press release above:

The U.S. Centers for Disease Control and Prevention found bisphenol A in the urine of over 95% of people they tested. Alarmingly, the median level of bisphenol A found in humans is higher than the level that causes adverse health effects in animal studies.

Sources

Bisphenol-A is commonly used to make clear polycarbonate plastic for baby bottles and is also found in:

• The multi-gallon plastic bottles used for water delivered to homes & offices
• Hard, often-colored, plastic water bottles used for personal use
• Children’s toys
• Dental sealants and epoxy adhesives
• Epoxy linings of food and beverage cans
• Microwavable food containers
• Drinking water (through landfill run-off)

The chemical leaches from plastic into food or liquid, especially when exposed to heat, acidic or basic substances, and/or repeated washing with detergents and soaps.

Health Risks

Bisphenol-A is an endocrine-disrupting (estrogen-mimicking) chemical tied to developmental, neuronal, and reproductive disorders. From the press release above:

Scientists have linked very low doses of bisphenol A exposure to cancers, impaired immune function, early onset of puberty, obesity, diabetes, and hyperactivity, among other problems.

See the full report for a succinct discussion of the potential health risks.

Importantly, these negative effects may be observed at very low exposure levels (less than one part per billion - ppb). Instead of a linear response curve (higher dose = greater harm), recent studies suggest that the bisphenol-A response curve may be an inverted “U” shape (lower dose = greater harm than higher dose).

Evidence Builds

The findings in the report aren’t just some “extremist group’s” views, as some may try to paint the results. They’re supported by a recent comprehensive review published in the National Institute of Environmental Health Sciences’ (NIEHS) leading journal, Environmental Health Perspectives:

An Extensive New Literature Review Concerning Low-Dose Effects of Bisphenol A Shows the Need for a New Risk Assessment (free full-text)

Bisphenol A (BPA) is the monomer used to manufacture polycarbonate plastic, the resin lining of cans, and other products, with global capacity in excess of 6.4 billion lb/year. Because the ester bonds in these BPA-based polymers are subject to hydrolysis, leaching of BPA has led to widespread human exposure. A recent report prepared by the Harvard Center for Risk Analysis and funded by the American Plastics Council concluded that evidence for low-dose effects of BPA is weak on the basis of a review of only 19 studies; the report was issued after a delay of 2.5 years. A current comprehensive review of the literature reveals that the opposite is true … no industry-funded studies have reported significant effects of low doses of BPA, although > 90% of government-funded studies have reported significant effects.

Recommendations

Here’s a tip sheet from EC that provides useful suggestions for reducing your family’s exposure to bisphenol-A, including:

• Choose baby and drinking bottles made of:
• • Glass
  • Safer-plastic (#1, #2, or #5 in the recycling triangle on the container)
  • Stainless steel (include sippy cup adapters)
• Avoid polycarbonate and PVC food containers (#7 and #3 in the recycling triangle, respectively. Polycarbonate bottles also sometimes have the letters “PC” printed on them.).
• Choose metal feeding utensils and enamel or ceramic plates.
• Avoid foods wrapped in plastic.
• Use glass when heating food or liquids in the microwave.
• Avoid using hot water or harsh detergents when washing plastics.
• Choose PVC-free toys and teethers. Keep plastic toys out of children’s mouths.

More study is clearly needed regarding the specific human health effects of low-dose bisphenol-A exposure. If, as current laboratory research seems to suggest, the negative effects are indeed present, bisphenol-A use needs to be phased out.

Regardless of those findings, as EC notes, consumers need to be better informed of potential health risks posed by different commonly used chemicals and greater testing should be required for all new chemicals before they are introduced into the marketplace.

This entry was posted on Tuesday, March 13th, 2007 at 11:16 pm and is filed under Child Nutrition, Hormone Issues, Other Toxins. You can follow any responses to this entry through the RSS 2.0 feed. You can leave a response, or trackback from your own site.