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Navajos, Amerindians, and Type 2 Diabetes

April 24, 2005 10:41 AM

As you may know, the Navajo as well as other Amerindians (Eskimo, Pima, Mexican and others) living in North America, suffer from high rates of adult onset or Type 2 diabetes. Current knowledge suggests this group a native Americans arrived from parts of Asia by migrating over a land bridge that formed across the Bering Sea during the last Ice Age. This was about 15,000 years ago, though the date is still in flux, when water levels around the Earth were about 100 meters below their current level (the water was trapped in the ice). The region of Asia feeding migrants over the land bridge was populated by Mongols and all Amerindians living today show the peaked incisor shape characteristic of Mongol people. DNA testing is likely to establish further evidence of the primarily Mongoloid source of Amerindian genes, if it hasn't already been demonstrated.

Right now, Type 2 diabetes is at high levels among nearly all Amerindians who have departed from their traditional hunter/gatherer ways. A traditional Eskimo male has about 11% body fat. A city-dwelling Eskimo male has about 33% body fat. Diabetes is rare among Eskimo who follow traditional ways and it is above 30% for those who don't. They differ dramatically in strength as well as tested by grip strength in published research. Pima indian males often carry body fat in excess of this latter figure. And, the incidence of diabetes among the Pima differs according to their diet and activity levels; those living in the US have diabetes rates near 50%, while those living in Mexico have rates far below this.

The Mexican Pima do hard agricultural work and eat a simple, natural diet (if too high on carbohydrate-laden beans and corn). The US Pima live on some of their own farmed food, but the bulk of their food comes from the same sources we all rely upon. But, the remote locations of the Pima and Navajo reservations makes the availability of fresh fruits and vegetable problematic (few realize the health benefits that flowed from the US Interstate Highway system that made the trucking of fresh foods to rural areas possible). Thus, their diet relies on long-shelf life manufactured foods.

The reservation areas are also limited in their agricultural potential, so there is less home-grown produce among the US Pima than among the Mexican Pima. And, in both instances, as well in all other reservations, the lack of private property limits the incentives the users have in developing their land for agricultural use. (I published two articles long ago on the adverse incentives and diminished productivity of the Ejido land reform areas in Mexico and the same points apply to reservations where property is held in common rather than individually.)

So, add it all up: a paucity of fresh, nutritious foods, dependance on high starch food sources, low physical activity, high abdominal fat deposits, and perhaps a genetic disposition to direct nutrients to fat (though this "thrifty gene" hypothesis is off the mark in my estimation) and you get a sense of why diabetes is stalking the Amerindian population. Transpose the same set of conditions on the rest of the American population (and slowly this is taking place and is present now in some rural areas) and you set the conditions for a wave of Type 2 diabetes which is now beginning to gather force in the US.

These were my concerns when I wrote of a trip my wife and I took to Santa Fe, where I was attending a conference at the famous Santa Fe Institute. As we drove there through Navajo country, I had these thoughts which were published in the Price-Pottenger Newsletter. This link is to their site A Visit to Navajo Country

· Evolutionary Fitness

Comments

Posted by: Flower Online [TypeKey Profile Page] at September 12, 2006 7:18 AM

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