The drug may even alter genes in the tongue associated with taste bud development, per the research, which was presented at ENDO 2024, the Endocrine Society’s annual meeting in Boston.
This theory, along with studies in mice showing that the absence of GLP-1 hormones dramatically reduced the perception of sweetness, led researchers to believe that semaglutide would improve taste sensitivity in people.
Semaglutide Improved Sensitivity to Sweet Flavors
In this “proof of concept” study, investigators randomly assigned 30 women to receive weekly injections of either 1 milligram (mg) of semaglutide or placebo for 16 weeks. Participants were on average 34 years old with a body mass index (BMI) of 36.4.
Before starting the study, researchers measured the participants’ current sensitivity to different tastes, using 16 taste strips infused with four different concentrations of sweet, sour, salty, and bitter substances. The women were asked to identify the taste of each strip, and every correct answer counted as one point, with a possible total of 16 points overall.
Researchers also took a small biopsy of each participant’s tongue, to analyze genes tied to taste buds.
Finally, investigators conducted MRI brain scans of the women as a sweet solution was dropped onto their tongues, both before and after a meal.
These tests were repeated on the two groups at the end of the study period.
At the end of the study, the women taking semaglutide increased their taste sensitivity from 11.9 to 14.4 points. They also showed decreased activation in the brain’s reward system.
The tongue biopsies also found that genes associated with taste bud development and regrowth were different between the semaglutide and placebo groups.
“This paper highlights the complex interactions between taste, hormone signals, diet, and weight change,” says Alex DiFeliceantonio, PhD, a researcher and an assistant professor in human nutrition, foods, and exercise at Virginia Tech in Blacksburg, Virginia, who was not involved in the study. “We still have so much to learn,” she says.
But researchers haven’t shared some aspects of the study design, so it’s hard to tell if they controlled for other factors that affect taste perception and gene expression on the tongue, such as changes in dietary habits and weight loss, says Dr. DiFeliceantonio. “Both of which could have changed as a result of being on the drug,” she adds.
Why Does Taste Sensitivity Matter for Weight Loss?
These findings could help experts understand and potentially adjust taste preferences in people with obesity, says Dr. Jensterle Sever.
They may also resonate with some doctors who’ve reported that patients say their interest in certain foods has changed since they started a GLP-1, she says.