The glucagon-like peptide-1 (GLP-1) receptor agonist semaglutide (Ozempic, Wegovy) enhances taste sensitivity, changes brain responses to sweet tastes and may even alter expression of genes in the tongue associated with taste bud development, according to new research presented at the annual meeting of the Endocrine Society, held in Boston.
“Some studies have reported that individuals living with obesity often perceive tastes as less intense,” noted Mojca Jensterle Sever, PhD, of the University Medical Centre in Ljubljana, Slovenia, who presented the work. Research also suggests that “populations prone to obesity have an inherently elevated desire for sweet and energy-dense foods,” she continued.
Studies in animal models have also previously shown that GLP-1 plays an important role in taste sensitivity, but it was not known if this hormone also influenced human taste perception.
In this proof-of-concept study, researchers randomly assigned 30 women with polycystic ovary syndrome (PCOS) to either 1 mg of semaglutide, administered once a week, or placebo for 16 weeks. Participants were on average 34 years old with a body mass index (BMI) of 36.4. Participants with PCOS were selected with the “aim to reduce variability in taste perception across different phases of the menstrual cycle,” Dr. Sever said.
Prior to the intervention, researchers tested participants’ taste sensitivity using 16 taste strips infused with four different concentrations of sweet, sour, salty, and bitter substances. Participants were asked to identify the taste of each strip. Every correct answer counted as one point, with a possible total of 16 points overall. Tongue biopsies were conducted for gene expression analysis.
Researchers also used functional MRI (fMRI) to evaluate brain responses to a series of calorie-dense, low-calorie, and non-food visual cues as well as to sweet taste stimulus. A sweet solution was administered on the tongue 30 minutes before and after participants consumed a standardized meal: a high-protein enriched nutritional drink.
These tests were repeated after 16 weeks.
The semaglutide group also exhibited decreased activation of the putamen (a structure in the brain involved with the brain’s reward system) on fMRI in response to calorie-dense cues. In response to sweet taste stimulus, those taking semaglutide showed increased activation of angular gyrus on MRI compared with the placebo group. The angular gyrus is part of the brain’s parietal lobe and is involved with language, memory, reasoning, and attention.
Lastly, researchers identified differential mRNA expression in the genes EYA, PRMT8, CRLF1, and CYP1B1, which are associated with taste bud development, renewal, and differentiation.
The findings are “fascinating, because we think about all of the factors that this new class of agents are able to improve, but taste is often not something that we look at, though there have been very strong associations,” said Gitanjali Srivastava, MD, of Vanderbilt University, Nashville, Tennessee, who moderated the session.
“Is it possible that another mechanism of action for this class of agents is perhaps indirectly altering our taste perception,” she posited, and, because of that, “we have an altered sense of satiety and hunger?”
Dr. Sever noted Dr. Several limitations to the study, including that only specific tastes were evaluated in a controlled study environment, “which may not reflect everyday experience,” she said. Taste perception can also vary widely from person to person, and changes in mRNA expression do not necessarily reflect changes in protein levels or activity.
“Our study should be seen and interpreted as a proof-of-concept study,” Dr. Sever added, with additional research needed to explore the relationship between semaglutide and taste perception.
Dr. Srivastava consults for Novo Nordisk, Eli Lilly, and Rhythm Pharmaceuticals. She has received research grant support from Eli Lilly. Dr. Sever reports no relevant financial relationships.
A version of this article appeared on Medscape.com .