DALLAS Feb. 16, 2007 Scientific studies of why foods such as Brussels sprouts and stout beer are horribly bitter-tasting to some people but palatable to others are shedding light on a number of questions, from the mechanisms of natural selection to understanding how our genes affect our dietary habits.
Dr. Stephen Wooding, a population geneticist at UT Southwestern Medical Center in Dallas, studies how slight variations in genes give rise to variations in traits among a given human population.
Part of Dr. Wooding's research focuses on variations in the genes responsible for bitter-taste receptors, tiny receptacles on the tongue that intercept harsh-tasting chemicals from food. Each of these genes comes in several forms, and the forms you carry help determine how you perceive bitter-tasting compounds.
The ability to taste or not taste bitter foods might have played a role in human evolution and may today account for such health-related behaviors as smoking and vegetable consumption, Dr. Wooding said. He will present an overview of his research on the bitter-taste receptor today in San Francisco at the annual meeting of the American Association for the Advancement of Science. The title of his talk is "Evolution: A Study in Bad Taste?"
In the 1930s, scientists discovered differences in the ability of humans to taste a bitter synthetic compound called phenylthiocarbamide, or PTC, and they determined that the trait was controlled by genetics (the actual gene for PTC sensitivity was discovered in 2003). For PTC "tasters," even tiny concentrations of the compound are extremely bitter, while "nontasters" experience little or no taste to the same concentration of PTC.
"In some ways, bitter-taste sensitivity seems to be a trivial trait, but early geneticists recognized that this trait was special, for a variety of reasons," said Dr. Wooding, an assistant professor with UT Southwestern's Eugene McDermott Center for Human
Contact: Amanda Siegfried
UT Southwestern Medical Center