Thursday, May 15, 2008

You are what you eat (from)

It's not just food that makes us fat.

In studies presented yesterday at the 16th European Congress on Obesity in Geneva, Switzerland, researchers have shown that exposure to certain chemicals early in life can promote obesity.

Three groups of researchers presented findings on the effects of endocrine disruptors, chemicals that mimic the effects of hormones, on the development of mice.

The chemicals include:
  • Bisphenol A (BPA), used in polycarbonate plastics, like plastic containers, plastic wrap, and the linings of food cans
  • Perfluorooctanoic acid (PFOA), a greaseproofer used in food containers, like microwave popcorn bags and pizza boxes
  • Tributylin, used in plastic food wrap
These chemicals can leach into food and has been found in the blood of people living in developed countries.

The researchers, from Tufts University, the EPA, and UC-Irvine, demonstrated that mice exposed to these chemicals in utero and early in life were fatter as adults than control mice, even when their food intake and activity level were the same. The exact mechanism of action is unclear, but the investigators noted differences in the ways these mice regulate glucose and respond to insulin, and in levels of the hormone, leptin. The effects were not seen when mice were exposed only later in life.

I was told as a new mother that bottle-fed babies have a greater chance of becoming obese than breast-fed babies, probably because they don't learn to regulate how much they eat. "Just finish this bottle, and we'll be done, sweetie." Or maybe it was because of certain ingredients in commercial baby formula. These studies make me think that it's not just what's in the bottle, or how much they drink from the bottle, but the bottle itself that predisposes to obesity.