Obesity is killing off people’s taste buds, and now scientists can explain why

The case of the missing taste buds.
The case of the missing taste buds.
Image: AP Photo/Winfried Rothermel
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Through the years scientists have gleaned that obesity can impact a person’s ability to taste, but until recently it’s been unclear why.

Researchers at Cornell University report the discovery that, in mice, a tiny amount of inflammation driven by obesity actually reduced the number of taste buds on their tongues. Their work was published this week (March 20) in the journal PLOS Biology, and it may wind up aiding the development of new therapies to alleviate what’s called “taste dysfunction” among people who suffer from obesity.

As part of their work, the researchers split lab mice into two groups and fed each group a different diet for eight weeks. The first group ate a standard rodent chow, comprised of 14% fat, 54% carbohydrate, and 32% protein. The second group got a high-fat diet consisting of 58.4% fat, 26.6% carbohydrate, and 15% protein, which led to obesity in the group.

After eight weeks, the researchers examined the two groups of mice and noticed the obese mice had 25% fewer taste buds.Taste buds typically consist of 50 to 100 cells and usually last about 10 days before they are cycled out and replaced. Those cells are able to taste at least five different tastes, too: salt, sweet, bitter, sour, and umami.

The Cornell scientists attributed the loss of taste buds in the lab mice to the build-up of a fatty tissue called adipose, one of the body’s tools for storing fat. Adipose produces little proteins called cytokines, which can cause inflammation, and upset the balance of cell death and renewal.

Of course, this work involve mice. But it may well also apply to humans. If that’s the case, life could get a lot more flavorful for people who’ve long been deprived of that sensory experience. That’s major news for a lot of Americans, in particular. Nearly one in three people in the US—31.4%—today are obese, according to recently published data (pdf) by the US Centers for Disease Control and Prevention.