Obesity kills taste buds and dulls taste sensation finds study

By Dr. Ananya Mandal, MDMar 20 2018

According to a new study from researchers at the Cornell University, obesity can actually dull the taste buds as has been suspected for a long time. The study appeared in the latest issue of the journal PLoS Biology yesterday (20th of March 2018).

Close Up Photo Of Healthy Human Tongue Taste Buds Macro. Image Credit: Radu Bercan / Shutterstock

Robin Dando, assistant professor of food science at Cornell University, and graduate students Andrew Kaufman and Ezen Choo, in their study fed lab mice a special diet that would make them as fat as possible. Dando directs the Cornell Sensory Evaluation Facility. The mice ate up and with this unhealthy diet soon became overweight said Dando. Eight weeks after they were started on this feed, they were euthanized and their tongues were studied. The tongues of these fat animals were compared with those of skinnier animals.

Dando says that it is a known fact that obese people tend to have a duller sense of taste as they gain weight. There have been studies which have shown that when given taste tests, the obese individuals do poorly compared to their normal weight counterparts. The reason behind this was not known. To understand this Dando conducted this experiment. He noted that with fatty diet, the taste buds slowly withered. “The obese ones have about 25 percent fewer taste buds,” he said. In the fat mice he noted that taste buds were dying off faster and it was taking more time for them to be replaced or renewed.

In this same experiment, the researchers also included two other groups of mice. One group was genetically modified in such a way that they would not gain weight despite having been fed a high fat diet. Dando says these were “obesity resistant” mice. At the end of eight weeks, these mice also had their tongues studied. It was noted that their taste bud concentration remained normal like their thinner counterparts. This meant that it was not the diet that was killing off the taste buds but the obesity itself.

Another group of mice they took were also genetically modified. These could not produce TNF alpha which is normally responsible for inflammation in the body. The levels of TNF alfa rises with certain inflammatory conditions and also in obesity in humans as well as in mice. Lack of TNF alfa in these mice meant less inflammation. These mice were also given a high fat diet. At end of eight weeks their tongues showed no loss of taste buds. This means that loss of taste buds occur only when there is a high rate of background inflammation related to TNF alfa.

Dando found that this loss of taste buds was not a permanent one. As the obesity comes down among bariatric surgery patients, taste buds come back. This research could be the basis for further studies and drug development says Dando.