wired.com - One of the best-elaborated hypothesis suggests that lack of exposure to infections in childhood keeps the various components of the immune system from learning how to hold themselves in balance. If this sounds familiar, it’s because it’s a version of the “hygiene hypothesis” (past posts here, here and here), which says that a too-clean childhood can lead to allergies later in life.
The diabetes version of this hypothesis explores whether conditions that are a proxy for exposure to infections — not having older siblings in the house, not attending day care, being born by Caesarean — can have an effect on the occurrence of diabetes. No clear culprit has been found yet.
Some researchers say it is possible that obesity may play a role. In type 2 diabetes, tissues in the body that receive the hormone insulin, which regulates blood sugar, become insensitive to it. In type 1, the body destroys the insulin-producing cells. But an “overload” hypothesis is now suggesting that if a child is obese to begin with, that could prime the insulin-producing cells for failure, with the auto-immune attack pushing them over the edge.
If obesity is an explanation, it’s not a comforting one. As the CDC’s National Center for Health Statistics noted today, a whopping percentage of United States adults — 36 percent — are obese. And the trend is not reversing. By 2048, according to Johns Hopkins researchers whose work is discussed in my story, every adult in America will be at least obese of the current trend continues.
