Exposure to chemicals may change the way people (and other creatures) deposit fat within their bodies which may play a role in obesity. Since Obesity is also associated with diabetes, cancer and heart disease it is also possible that the same chemicals play a role in development of these diseases as well.
A study published in this month's (April) issue of Environmental Health Perspectives by Ruzzin et al.describes the effects of exposure to Persistent Organic Pollutants (POPs) on insulin and lipid profiles in rats. POPS is a term usually used to describe a set of chemicals that are very slow to degrade, accumulate in body fat, and concentrate as you move up the food chain. The POPs in this study were isolated from farmed Salmon, and it is thus not much of a stretch to expect that people consuming farmed salmon would be exposed to a similar mixture of this particular soup.
It is important to keep in mind that anything with animal fat will contain POPs, so avoiding salmon consumption may not be particularly protective. An earlier and equally intriguing paper by Somme et al. 2009 showed altered fat deposition when newborn rats were exposed to Bisphenol A. So what's going on with the current obesity epidemic? Are chemical exposures playing a role? Hopefully further research will elucidate this mystery.
For those interested in protecting their health: eat low on the food chain (bugs, shrimp, vegetables). And, avoiding drinking or eating things that have been packaged in BPA-containing plastics would be a simple way to reduce BPA exposure.
The original "dirty dozen" POPs have been banned in the US. Exposure, however, is universal because POPs accumulate in fat, and we pass them on to our children during pregnancy and lactation. Anyone interested in a multi-generational fat biopsy study? Bisphenol A is not banned and is believed to be rapidly excreted in urine (Yeah!).