While the Amish themselves have little interest in modern technological conveniences, scientists have for many years found this tight-knit community located mainly in Pennsylvania, Ohio and Indiana to be quite a willing and invaluable research partner.
The Amish started emigrating from northern Europe to the United States in the 18th century. Of the 40,000 Amish currently residing in Lancaster, Pa., 99 percent can be genetically traced back to 122 of the original 300 founders. That rate of genetic homogeneity makes them ideal for scientific study.
Dr. Alan Shuldiner, the John A. Whitehurst Professor Medicine at the University of Maryland School of Medicine, and his group have been studying the Amish for about 15 years, looking specifically at genetically complex diseases like diabetes, dyslipidemia and cardiovascular disease. Dr. Shuldiner, who also serves as director of the Program in Genetics and Genomic Medicine and head of the Division of Endocrinology, Diabetes and Nutrition at the University of Maryland, discussed his findings at a recent Medicine Grand Rounds presentation at Weill Cornell Medical College, entitled "Quilting Needles, Lancaster Haystacks and the Search for Genes for Diabetes and Related Traits."
Through the Amish Research Center in Lancaster and the laboratories in Baltimore, Dr. Shuldiner and his team of about 60 researchers are conducting a dozen active studies involving more than 4,000 Amish.
In one, the Amish Family Diabetes Study, researchers looked at the 15 genes known to increase susceptibility to increased body mass index and obesity in about 1,400 Amish. While the rate of obesity among the Amish is comparable with that of the U.S. population at large, the prevalence of diabetes is about half that of non-Amish whites in this country.
"The Amish are much more physically active than we are," Dr. Shuldiner said. "It's likely that high levels of physical activity protect them from diabetes."
Dr. Shuldiner also noted that overweight Amish follow a different pattern of weight gain than the typical American, adding pounds later in life when many Americans are obese even as children.
"That pattern may also protect them from diabetes," Dr. Shuldiner said.
The Amish's genetic homogeneity "makes these complex genetic diseases somewhat less complicated," Dr. Shuldiner said, "so the disease genes can be tracked through families and through the population with somewhat greater ease."
In another study, researchers are attempting to identify genes that could predict how an individual may respond to medications used to treat cardiovascular diseases. That would be a breakthrough for any person suffering from cardiovascular disease, regardless of ethnicity. But by searching for that gene or genes among the genetic homogeneity of the Amish, the task becomes less overwhelming.
"The fun thing about the Amish is we can find out who there families are," Dr. Shuldiner said. "We can track them all the way back to the start of these genetic mutations."