Diabetes Gene Findings Don't Change Conventional Wisdom: Eat Well and Exercise

Studies appearing today in *Science *and Nature Genetics have tripled the number of genes suspected in increasing the risk of developing type 2 diabetes, the most common, obesity-associated form of the disease.

The New York Times was quick to proclaim the findings' potential:

Four reports published today have tripled the number of variant genes known to underlie type 2 diabetes, providing researchers with a clutch of novel insights into the biology of a disease that affects 170 million people worldwide.

The sudden spate of new genes marks an acceleration, and perhaps a turning point, in the ability to find disease genes, the long promised payoff from the human genome project that began in 1989.

But lost in the clamor was a sense of how closely the genes link to the disease. The Boston Globe put this right up top:

Together, the genetic defects account for about 5 percent of the risk of getting the illness, said David Altshuler, associate professor of genetics and medicine at Harvard Medical School and a leader of one of the four teams that included the Broad Institute of Harvard and MIT.

"The picture that is emerging is of multiple genes, each with a modest effect" on diabetes, he said.

DeCode Genetics, the Icelandic biotech company responsible for one of the studies, has developed a test for one of the variants, ostensibly to help people decide whether to make lifestyle changes that could prevent the disease from developing.

It's hard to see, however, what benefit could be provided by knowledge of one's defective genes. More than 20 million Americans have diabetes; the risk is so high, and so clearly associated with obesity and inactivity, that eating better and exercising more is a treatment recommended to everyone, regardless of genetics.

The prognosis is better for the findings' potential to spur new treatments:

"The pharmaceutical industry is absolutely salivating at all of these studies because they represent the best validation of a new drug target," said Dr. Francis Collins, director of the National Human Genome Research Institute and a leader of another of the teams. But Collins cautioned that it could be a decade before patients see any new drugs from the research.

Studies Find More Genes Underlying Diabetes [New York Times]

Genetic understanding of diabetes deepens [Boston Globe]

Image: Marshall Astor