What’s to blame? Mounting evidence partly points to manmade toxins. Some people, it appears, gain weight not because they are sofa spuds but because
of exposure to our brave new world.
This isn’t another crackpot theory. A mountain of peer-reviewed evidence points to two familiar chemical villains—bisphenol A (BPA) and phthalates. Studies show these complex organic chemicals (also known as plasticizers) disrupt hormones that control weight, triggering increased production of fat cells in some people.
BPA, the better known of the two, is a synthetic estrogen used in the manufacture of certain plastics and epoxy resins. It’s typically found in the lining of canned foods, food packaging, bottle caps and bottles, plastic water pipes, resinous dental fillings, shower curtains, vinyl wallpaper, cash register receipts, and flame retardants.
The good news? Most manufacturers have voluntarily eliminated BPA from baby bottles. The bad news? Formula cans are still lined with it.
Phthalates have hit the radar of only the most informed U.S. consumers. These oil-based compounds are typically used to make household items harder or more flexible. Researchers trace approximately 90% of adult exposure to food (mostly meats), but other sources include certain household cleaning products, cosmetics, vinyl flooring, shower curtains, and children’s toys. In late 2007, researchers discovered phthalates in pizza boxes and fast-food wrappers.
How much environmental toxins account for human obesity still isn’t clear. Wayne State University researcher Douglas Ruden, PhD, calls the toxin-obesity link “a well-substantiated theory in the scientific community.” The Canadian government and some in Europe, he notes, prohibit BPA in foods. But it’s “business as usual” in the United States—with the chemical industry in the driver’s seat.
The public health challenge is complicated because plasticizers are so ubiquitous and persistent. “Many have very long biological half-lives, so they stay in our bodies for a long time—even for decades,” says Arya Sharma, MD, PhD, chair of cardiovascular obesity research and management at the University of Alberta in Edmonton.
How ubiquitous? Odds are, the plastic interior of your automobile (dashboard, side panels, seats, and ceiling) is loaded with BPA and phthalates. On hot days, these plasticizers are released into the passenger cabin—for you to breathe as you drive. Your coffee is also likely laced with BPA, thanks to the plastic parts in most electric coffee makers. Ditto for most mobile phones.
“Almost everybody tests positive for these plasticizers in their blood,” Ruden notes. “A premature baby in a plastic incubator with plastic tubes is being pumped full of plasticizers.”
“There’s no question these compounds exist, accumulate in fat tissue, and promote obesity and other metabolic changes in the body,” Sharma says.
Ruden advocates consumer awareness coupled with swift federal intervention, but he isn’t particularly optimistic. “If BPA is eventually banned,” he says, “the chemical industry is likely to switch to another chemical that hasn’t been tested yet and that 10 years from now is found to be bad too.”
Finding acceptable substitutes begins by doing your homework and, in some cases, playing detective. When in doubt, contact the manufacturer and ask whether these potentially dangerous chemical compounds are in their products. While you’re at it, consider calling your representative on Capitol Hill and letting them know this issue is important to you and yours.
Concerned consumers can reduce their exposure to BPA and phthalates in the following ways:
- Buy water and baby bottles labeled as BPA free or use nonplastic equivalents.
- Avoid canned beverages and foods; fresh is likely safer.
- Choose plastics with the recycling codes 1, 2, or 5. Avoid 3 or 7.
- Be aware that phthalates are sometimes identified by chemical shorthand: DBP, DEP, DEHP, DMP, or BZBP.
- Don’t cook with plastics and don’t place hot foods in plastic containers.
- On hot days, let your car air out before you get inside.