Cats and sweet tastes

June 7, 2012

Jiang P, Josue J, Li X, et al. Major taste loss in carnivorous mammals. Proc Natl Acad Sci U S A 2012;109:4956-4961.

Believe it or not, the ability to taste sweets is not universal. Sweetness is detected by a specific receptor protein (‘taste bud’) in the tongue. Cats are known to be insensitive to sweet tastes, at least behaviorally, but the specific reason was not known until a few years ago. These researchers analyzed the genes encoding the taste buds in twelve different carnivorous species, including cats. They found that those species such as cats, whose diet is exclusively meat-based, had lost the gene encoding the taste bud for sweetness. Other affected species included dolphins, sea lions, seals, otters, and hyenas. It appears that the ability to taste sweets has been lost in most carnivorous species – what a terrible loss! [MK]

See also: Li X, Li W, Wang H, et al. Pseudogenization of a sweet-receptor gene accounts for cats’ indifference toward sugar. PLoS genetics 2005;1:27-35. [Free, full text]