 |
|
|
 Health & Beauty | September 2007 
A Tale of Two Pimas
 Mark Roth - Pittsburgh Post-Gazette
go to original
| As Bonita Reid, 34, injects herself with her daily dosage of insulin, her three-year-old daughter, LaDania Reid, looks on at the Gila River Indian Community, south of Phoenix. (Mona Reeder/Arizona Republic)
 An ongoing series through October on the causes, complications and costs of type 2 diabetes. This piece explores important work being done to understand the disease.
|
They are 400 miles and two centuries apart.
On one end are the Pima Indians of the United States, living in the Gila River Indian Community near Phoenix.
The American Pima own pickup trucks, farm on tractors and eat an all-American diet. They also have one of the highest rates of type 2 diabetes in the world - 41 percent of all adults have the disease.
On the other end are the Pima Indians of Mexico, living in a remote corner of the state of Sonora, an area that only recently gained highway access. These closely related Pima farm with wooden plows pulled by horse or oxen, and their diet is dominated by corn tortillas.
Their diabetes rate? Just 9 percent.
That startling disparity shows just how important diet and lifestyle are in type 2 diabetes, said Dr. Eric Ravussin, the Douglas L. Gordon professor of diabetes and metabolism at the Pennington Biomedical Research Center at Louisiana State University.
Dr. Ravussin, who was involved in a pioneering study last year comparing the Mexican and American Pima, said that when he and fellow researchers got to the Mexican Indians' territory, "it was amazing to discover they were plowing the fields with wooden plows behind horses, and carrying wood and water like people living in the 19th century in northern Europe."
Their low-fat diet included corn tortillas, fresh peaches, vegetables, fish, and, only occasionally, chicken or beef, he said.
The American Pima, on the other hand, are just as sedentary as many other Americans, and often eat a high-fat diet that has its roots in their first encounters with white settlers in the 1800s, Dr. Ravussin said.
Before the Gold Rush of the 1840s, the American Pima practiced subsistence farming and used water from the Gila River to irrigate their crops.
When white settlers arrived, though, they grabbed most of the water for their farming, and the Pima ended up relying on U.S. government food supplies that included lots of flour and lard.
In fact, the "Indian fry bread" that is cooked in lard comes from those days, and was never part of the Pimas' traditional culture, he noted.
Less exercise and more fat obviously accounts for a large part of the American Pimas' high diabetes rate. But genetics plays a role, too, Dr. Ravussin's research found.
While the Mexican Pima had a 9-percent diabetes rate, their non-Indian neighbors, who had a similar lifestyle and diet, had an even lower 5 percent rate. "In general, the Mexican Pima have double the diabetes rate of other Mexicans, and this is the genetic side of things."
Scientists affiliated with the National Institute of Diabetes and Digestive and Kidney Diseases have been doing diabetes research at the Gila River Indian Community for more than 30 years. In 1993, they found the Pima had a gene that caused the body to absorb more fatty acid from foods than normal.
Dr. Ravussin and others believe the genetic susceptibility to diabetes may be linked to "thrifty genes" that evolved over thousands of years to protect early humans during times of drought and famine by helping their bodies absorb salt and store fat.
In affluent societies today, such threats are greatly diminished, and the once-protective genes are now culprits in creating high blood pressure, heart disease and diabetes.
"To me there's no doubt that humankind was not designed over the millennia to cope with our present environment," Dr. Ravussin said, "but was designed to cope with periods of feast and famine. This having plenty of everything is something pretty new."
Those with Asian roots - including many American Indian tribes - seem to have a special genetic vulnerability to diabetes.
One projection estimated that diabetes cases would increase by 46 percent worldwide between the years 2000 and 2010, but the biggest increase - nearly 60 percent - would occur in Asia, especially as countries like China adopt a more Westernized lifestyle.
It is further evidence, Dr. Ravussin said, that in diabetes, as with other diseases, "genetics loads the gun and environment pulls the trigger."
Mark Roth can be reached at mroth@post-gazette.com or at 412-263-1130. |
| |
|
Vallarta Weddings
Tell a Friend
Site Map
Print this Page
Email Us