Why do we like fatty foods so much? We can blame our taste buds.
Our tongues apparently recognize and have an affinity for fat, according to researchers at Washington University School of Medicine in St. Louis. They have found that variations in a gene can make people more or less sensitive to the taste of fat.
Scientists have agreed that the tongue can sense five distinct tastes but differed over whether our taste buds can detect fact. New research now finds that the tongue can recognize and has an affinity for fat and that variations in a gene can make people more or less sensitive to the taste of fat in foods.
The CD36 discovery follows research that had identified a role for the gene in rats and mice. Scientists had learned that when animals are genetically engineered without a working CD36 gene, they no longer display a preference for fatty foods. In addition, animals that can't make the CD36 protein have difficulty digesting fat.
Our diet contains fat, mainly in the form of triglycerides, which are made of fatty acids linked to glycerol. In the taste test, the researchers presented subjects with two types of fat. Some cups contained a free fatty acid. Others contained triglycerides.
Pepino and Abumrad knew from animal studies that CD36 is activated by fatty acids but not triglycerides. Human subjects, however, were able to taste both. Pepino believes that's probably due to the activity of an enzyme called lipase in the saliva that breaks the triglycerides, releasing the fatty acids while the fat is still in the mouth.
Funding for this research comes from the National Center for Research Resources and the National Institute of Diabetes and Digestive and Kidney Diseases of the National Institutes of Health (NIH), and by a grant from GlaxoSmithKline Consumer Healthcare Research Program.