The Pimas. Is this our future?

Philip J. Goscienski, M.D.

August 2008

Native Americans of our Southwest are known for their unique and masterful craftsmanship in basketry, rug weaving, pottery and jewelry making. Since the 1960s they have become known throughout the world for another, ominous, reason: type 2 diabetes.

Most Native American tribes from the Arctic Circle to the southern border of the United States are reeling from the consequences of a disease that did not occur among them until the 1930s; it is now their second leading cause of death. It's not because it went unnoticed until recently. The Bureau of Indian Affairs has monitored the health of the tribes under their jurisdiction since early in the 19th century.

The Pima tribe is working with U.S. Public Health Service scientists hoping to learn why this population is not only the most obese on the planet but has a rate of type 2 diabetes that is 6 times as high as that for Americans of European ancestry.

Luckily for the researchers the Pimas consist of two populations that are genetically identical but diverse in lifestyle. Nearly 2,000 years ago some members of the original tribe left the mountains of central Mexico and settled in the area that now includes the southern portions of Arizona and New Mexico.

Except for their genetic similarity the differences between the groups are profound. Most Mexican Pimas are farmers with almost no mechanized equipment and few laborsaving devices. They spend 22 hours per week in moderate physical activity. A lack of modern plumbing forces them to walk to their sources of water and to carry it back home. Their fat intake is minimal and they grow their own food.

The Mexican Pimas have very low rates of heart disease and type 2 diabetes. Older members of the tribe are active and they maintain normal weight as they age.

U.S. Pimas farm with modern machinery and some work in the offices of local casinos. Easy access to processed foods makes their diet much like that of most Americans, high in fat, sugar and refined grains. It's no surprise that they weigh, on average, nearly 60 pounds more than their genetically identical cousins in Mexico and the rate of diabetes in U.S. Pima women over the age of 55 years is an astonishing 80 percent.

Young Pima women have a high rate of gestational diabetes, a condition that leads to greater risk of complications of pregnancy. Their elevated blood sugar puts their offspring at higher risk of overweight and type 2 diabetes early in life. The latter condition often leads to kidney failure, an expensive, life-shortening complication of diabetes.

The Pima tribe represents the canary in the healthcare coal mine. The incidence curve of obesity and type 2 diabetes in the United States is following the same trajectory as that of these Native Americans. Like them, some of our twenty-somethings already experience heart disease, kidney failure, blindness and amputations.

It's painfully obvious from the Pima experience that although genes load the gun, lifestyle pulls the trigger. We can't unload the chamber but we can put a trigger lock in place that will protect future generations.

Philip J. Goscienski, M.D. is the author of Health Secrets of the Stone Age, Better Life Publishers 2005. Contact him at drphil@stoneagedoc.com.