Diamond, the Pulitzer Prizewinning author of "Guns, Germs and Steel: The Fates of Human Societies" (W.W. Norton, 1997) and winner of the National Medal of Science, researched current and historic type II diabetes rates among nine different population groups in 24 regions. He then examined the groups' food history, including improvements in farming, Westernization or urbanization.
He found that diabetes rates have risen in lock step with living standards for the populations now most prone to the disease, including Arizona's Pima Indians, U.S. Latinos, Pacific Islanders, Westernized Australian Aborigines, African Americans, and urban Asians and eastern Indians. When Yemenite Jews were airlifted to Israel from starving conditions several decades ago, their diabetes rates jumped from 4 percent to 13 percent. When New Guineans moved from a rural to urban setting, their diabetes rate shot from zero to 37 percent, he found.
"Diabetes is a disease of increasing affluence," he said. "People eat more and risk developing diabetic symptoms when they have more money."
Diamond's findings are consistent with a long-standing theory of an evolutionary advantage to insulin resistance, which would tend to favor populations with so-called "thrifty genes" that promote metabolism and storage of blood sugars, thus allowing their carriers to better survive periodic famines.
"Much like the gene that protects against malaria but also predisposes so many people of African ancestry to sickle-cell anemia, the 'thrifty gene' is a double-edged sword that becomes a liability only after living standards improve," Diamond said. "Until a stable food source is secured, the gene helps people survive famines, but afterward it puts them at risk for the dangers of diabe
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Contact: Meg Sullivan
megs@college.ucla.edu
310-825-1046
University of California - Los Angeles
4-Jun-2003