It is surprising enough to learn of the very existence of people who don’t have a sweet tooth, but it really does get more interesting. Those who have no interest in consuming lots of sugar (and who consequently stand a decent shot of looking great in that pair of jeans) may owe thanks to a pair of genes.
As reported in ScienceNow by Constance Holden, a research team at the National Institutes of Health subjected a multi-ethnic test population to a taste test of solutions ranging from 0 percent to 4 percent sugar content, then asked them to assign sweetness rankings.
Two variations of one specific gene were associated with those displaying higher sensitivity to sweetness. Individuals with both variations of the gene are most likely to be of European descent; the genetic variation is less common in Asia and Africa.
While the cause for this adaptation is unclear, NIH scientist and study co-author Dennis Drayna suggests a dietary basis:
“People who study diet and evolution have pointed out most of the high sugar-containing plants like sugarcane are tropical plants. So in northerly latitudes, you have to be more sensitive to sugar to find calories.”
Photo courtesy of D Sharon Pruitt, via Wikimedia Commons.