Diabetes and the law

There is a big discussion over the new planned ban on sugar filled drinks in NYC. One of the main arguments that people for the ban put forward is that sugary drinks are a factor in obesity, and that obesity causes diabetes. This is actually being shown to be false. The correlation between diabetes and obesity was actually the subject of my graduate study while I was in school. The data was interesting.

To understand why diabetes is not causal to obesity, we need to look at what diabetes is. There are two types of diabetes, one is a childhood onset, called type one, or insulin deficient diabetes. Type one diabetes is abbreviated as DM1, for Diabetes Mellitis 1. The old school abbreviation is IDDM, or insulin dependent diabetes mellitis. The other type is type 2, or insulin resistant diabetes. This type is the one that is frequently blamed on obesity. It is abbreviated as DM2, or NIDDM.

Studies over the past 15 years are showing that the obesity is merely a symptom of the disease that appears to have a genetic component. What they are finding is that to get Type 2 Diabetes you need to have some combination of a variety of already-identified genetic flaws which produce the syndrome that we call Type 2 Diabetes. Only one in five people who are obese have diabetes, and nearly one quarter of people who are diagnosed with type two diabetes are not obese.

A study done in 1998 of the prevalence of diabetes among twins produced some interesting results. What it showed was that identical twins have an 80% concordance for Type 2 Diabetes, but that non identical twins had much lower concordance. This kind of finding begins to hint that there is more than just bad habits to blame for diabetes. A high concordance between identical twins which is not shared by non-identical twins is usually advanced as an argument for a genetic cause, though because one in five identical twins did not become diabetic, it is assumed that some additional factors beyond the inherited genome must come into play to cause the disease to appear.

 Certain genes have been found that are markers for type 2 diabetes. In people of European descent: SHIP2, ENPP1, PPARG, TCF7L2, HNF4-a, PTPN, FTO, KCNJ11, NOTCh3, WFS1,  IGF2BP2, SLC30A8, JAZF1, CDKAL1, and HHEX. In non European descendants, there are different genes. The more of  these genes you possess, the worse the performance of the insulin producing Beta cells in the pancreas.

It has long been known that African-Americans have a much higher rate of diabetes and metabolic syndrome than the American population as a whole. This has been blamed on lifestyle, but a 2009 genetic study finds strong evidence that the problem is genetic.

In short, the scientific evidence is mounting that the medical community may have been mistaken in insisting that obesity was the cause of diabetes, rather than a symptom of a syndrome that results in diabetes. Using the law to remove the freedoms of individuals is a serious matter, and to do so by using a false premise is a tragedy.