Why adding salt makes fruit—and candy—sweeter
It’s one of life’s little ironies: Sweet foods get sweeter when you add a little salt. Now, scientists may have provided connoisseurs of salted caramel and grapefruit with the reason this culinary trick is worth its salt.
Your ability to savor food comes from the receptor cells in your tongue’s taste buds. Sweet tastes are detected by a family of receptors called T1R, which pick up both natural sugars and artificial sweeteners. Scientists originally thought disabling the T1R family would stop any responses to sweet stimuli. But in 2003, researchers showed that mice whose T1R genes had been genetically “knocked out” still liked the sugar glucose. The finding suggested there must be another way that mice—and possibly humans—sense sweetness.
Seeking an explanation, physiologist Keiko Yasumatsu of Tokyo Dental Junior College and colleagues turned to a protein that works with glucose elsewhere in the body: sodium-glucose cotransporter 1 (SGLT1). In the kidneys and intestine, SGLT1 uses sodium to carry glucose into cells to provide them with energy. Curiously, the protein is also found in sweet-responsive taste cells.
