Are Genes to Blame for Your Diabetes?
As genetic testing grows ever more sophisticated, some familiar explanations for the diabetes epidemic are coming under fire. Take the “thrifty gene hypothesis,” an idea first proposed in the 1960s to explain why some populations were at higher risk of obesity and diabetes than others.
“The idea was that throughout human history, food scarcity led to genetic variants that favored people who could store more calories,” explains Jose Florez, MD, PhD, a geneticist at the Broad Institute and Harvard Medical School. “When you place those people in an environment of caloric superabundance, they’re more likely to become obese.”
The argument makes powerful intuitive sense, but thus far the genetic evidence suggests diabetes risk doesn’t have much to do with evolutionary selection. “We have powerful ways of identifying whether this or that region of the genome has been selected for,” Mark McCarthy says. “I don’t think the data completely negates it, but I don’t see evidence in favor of it, either.”