Another theory, this one having nothing to do with Goldman Sachs: Arsenic disrupts thyroid-mediated gene regulation, and may be a cause of diabetes, as well as obesity. Arsenic, used predominantly to treat lumber for building, steeply increased in the 1970’s, roughly tracking the increase in diabetes and obesity (with a lag time). Moreover, the Southeastern US, with the chemical and lumber industry, as well as superfund sites and particular natural soil formations, has fairly high arsenic groundwater and sediment rates — and is the leader in diabetes and obesity:
1. Thyroid regulates genes related to metabolism, as well as inflammation and blood coagulation to some extent, Huang et al., “Thyroid hormone dependent regulation of target genes and their physiological significance,” Chang Gung Med J. 31:325-34 (2008) PMID: 18935790;
2. Arsenic disrupts thyroid hormone gene regulation, Davey et al., “Arsenic as an Endocrine Disruptor: Arsenic Disrupts Retinoic Acid Receptor–and Thyroid Hormone Receptor–Mediated Gene Regulation and Thyroid Hormone–Mediated Amphibian Tail Metamorphosis, “ Environ Health Perspect. 116: 165–172 (2008). doi: 10.1289/ehp.10131;
3. Arsenic exposure is correlated with Type 2 diabetes, Navas-Acien et al., “Arsenic Exposure and Prevalence of Type 2 Diabetes in US Adults,” JAMA 300: 814-822 (2008) PMID: 18714061; the historical increase in obesity roughly follows the increase arsenic use (graphics below) although I couldn’t find anything direct on this;
4. Although arsenic is found in drinking water and seafood at fairly low levels almost everywhere, e.g., Meltzer et al., “Fish arsenic may influence human blood arsenic, selenium, and T4:T3 ratio,” Biol Trace Elem Res. 90:83-98 (2002) PMID: 12666828; the Southeastern US notably has a high level of environmental arsenic from historical use of arsenic as a pesticide, as well as chemical plants in the area (see the Sierra Club, gulf coast water and sediment testing, here and here;
5. The Southeastern US has the highest rates of Type 2 diabetes and obesity (graphs from CDC below);
6. Environmental arsenic disrupts thyroid mediated gene regulation and causes obesity/diabetes en masse?
via MMR Weekly, October 31, 2008 / 57(43);1169-1173
via MMR Weekly, July 18, 2008 / 57(28);765-768
From this graph, one can see that starting in about mid 1970, the use of arsenic steeply increased (red line) in linear correlation with the use of arsenic in treated wood (green line).
Here’s the animated obesity map from the CDC (although many have disputed these data, it does show a trend, I think):
CDC trends in obesity 1985 2001