Plastics, Diabetes and Obesity

Things start to get interesting when the results human epidemiology and animal exposure studies meet.  Epidemiology studies of human exposures to a xenoestrogen like BPA show relationships between exposure and diabetes, or exposure and obesity.  But it is very difficult to say that exposure to a plastics component causes obesity, diabetes or heart disease.  People who are exposed to a lot of xenoestrogens may eat more canned food and have more BPA (or similar) circulating in their systems, but people who eat a lot of canned and packaged food may also eat poorly, exercise less, and/or be less educated compared to someone who has very little plastics exposure.  

This is why animal studies are so important.  When the results of controlled animal studies are similar to trends we are observing in people the case for concern about a particular chemical jumps.  Many people oppose animal studies for ethical reasons, but sometimes leaving questions unanswered is unethical as well.  

There is increasing evidence that chemicals in the environment may be contributing to diabetes and obesity. This is not to say that there is no such thing as good habits, but biochemical variables, set during early life, may make it harder to regulate things like blood sugar and weight.  For current reviews and discussion take a look at:

• Toxic environment and obesity pandemia: Is there a relationship?
• Impact of environmental endocrine disrupting chemicals on the development of obesity.

Here is animal evidence for a relationship between exposure to bisphenol A, (and possibly other chemicals that are structurally similar)  and diabetes: Bisphenol A Exposure during Pregnancy Disrupts Glucose Homeostasis 
in Mothers and Adult Male Offspring. As discussed in previous posts, nearly everyone is exposed to Bisphenol A (BPA) and probably to other xenoestrogens through consumption of food and beverages packaged in plastic.  It is an interesting study.  It shows that exposures during pregnancy will affect offspring into adulthood.  Whether or not this is happening in people is unknown, and not testable. 

Katzenellenbogen JA (1995). The structural pervasiveness of estrogenic activity. Environmental health perspectives, 103 Suppl 7, 99-101 PMID: 8593885
 

Newbold RR (2010). Impact of environmental endocrine disrupting chemicals on the development of obesity. Hormones (Athens, Greece), 9 (3), 206-17 PMID: 20688618
 

Alonso-Magdalena P, Vieira E, Soriano S, Menes L, Burks D, Quesada I, & Nadal A (2010). Bisphenol A exposure during pregnancy disrupts glucose homeostasis in mothers and adult male offspring. Environmental health perspectives, 118 (9), 1243-50 PMID: 20488778