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New research shows semaglutide modified a gene expression in the tongue to improve taste sensitivity in females with obesity. FG Trade/Getty Images
  • Everyone tastes foods differently, but people with obesity have a weakened sense of taste.
  • In a new study, researchers found that semaglutide helps improve taste sensitivity in women with obesity.
  • Study participants who took semaglutide experienced a modification in a gene expression in the tongue responsible for taste perception.
  • Participants also experienced a change in the brain’s response to sweet tastes.

Although there are five main flavor categories — sweet, sour, salty, bitter, and umami — not everyone will taste foods the same way.

Some people may be more sensitive to certain flavors than others. How a person smells food also affects how it tastes to them.

Additionally, certain factors, such as smoking, aging, certain medications, and obesity, may cause a person’s sense of taste to change over time. Past research has linked obesity to fewer taste buds on the tongue, leaving people with a weakened sense of taste.

Now, researchers from the University of Ljubljana in Slovenia have found the glucagon-like peptide-1 receptor agonist (GLP-1 agonist) semaglutide — the active ingredient in Wegovy and Ozempic — helps improve taste sensitivity in women with obesity.

Scientists report participants who took semaglutide experienced a modification in gene expression in the tongue that’s responsible for taste perception and a change to the brain’s response to sweet tastes.

The findings were presented on June 1 at ENDO 2024, the Endocrine Society’s annual meeting in Boston, MA. The research has not yet been published in a peer-reviewed scientific journal.

First presenting author Mojca Jensterle Sever, PhD of the Department of Endocrinology, Diabetes and Metabolic Diseases at the University Medical Centre Ljubljana and the University of Ljubljana in Slovenia told Medical News Today:

“Alterations in metabolic health can significantly affect taste perception, “Obese individuals might perceive sweet tastes as less intense and may need more sweet-tasting agents to satisfy their reward-producing need for sweet. Reciprocally, populations that are prone to obesity have been shown to have an inherently elevated desire for sweet diets. The mechanisms behind these alterations are not well elucidated.”

For this study, researchers recruited 30 women with an average BMI of 36.4 who received semaglutide or a placebo for 16 weeks.

“The eligibility criteria in our study aimed to control for as many covariates as possible that, alongside obesity, could affect taste perception, including sex, aging, diabetes, other serious chronic diseases, (and) smoking,” Jensterle Sever explained.

“Therefore, we selected a homogeneous group of women with obesity without serious chronic diseases or lifestyle habits that could influence taste perception. By selecting anovulatory women with polycystic ovary syndrome, we additionally aimed to reduce the variability of taste perception across different phases of the menstrual cycle.”

Over the 16 weeks of the study, researchers measured the taste sensitivity of participants using strips with concentrations of four basic tastes.

“Taste sensitivity relates to the detection threshold for different tastes,” Jensterle Sever said. “We assessed the taste sensitivity by 16 strips impregnated with four different concentrations of four basic tastes. We did not study the correlation between increased taste sensitivity and weight loss.”

Scientists used MRI scans to evaluate brain responses to a sweet solution the study participants were given before and after a standard meal. Each participant had a tongue biopsy conducted to evaluate the mRNA expression within their tongue tissue.

At the study’s conclusion, the research team discovered that study participants who took semaglutide had not only changes in taste perception but also alterations to their taste bud gene expression and their brain activity in response to sweet tastes.

Previous studies reported that patients treated with semaglutide have reduced intensity of desire for sweet, savory, and salty foods,” Jensterle Sever said.

“Our proof-of-concept study assessed only a specific taste in a study environment, which may not reflect everyday experience.”

“Taste perception can vary significantly from person to person, limiting the generalizability of our results,” she continued.

“Additionally, mRNA sequencing has inherent limitations and does not directly represent changes in protein levels or activity. Future studies will clarify whether the efficacy of semaglutide in treating obesity is also a ‘matter of taste’.”

While consuming calorie-dense palatable foods is pertinent to the onset and maintenance of obesity and diabetes, Jensterle Sever described taste as a potential gatekeeper for controlling food intake.

“[Taste] conveys important information about the perceptual quality and an appetitive and hedonic value of the ingested substances,” she explained.

“From the taste bud in the tongue, gustatory nerve fibers transmit the gustatory signal to the brain where the taste qualities are further distinguished, and the information is further transmitted to perceive the reward value of food and regulate food intake.”

“Improvements in taste sensitivity in the tongue and gustatory coding in the brain can potentially modulate the circuitry for ingestive decision-making, particularly when eating behavior becomes dysfunctional. Exploring the potential possibilities to modulate gustatory coding by pharmacological manipulation remains an intriguing clinical challenge.”

— Mojca Jensterle Sever, PhD, first study author

After reviewing this study, Mir Ali, MD, a board certified bariatric surgeon and medical director of MemorialCare Surgical Weight Loss Center at Orange Coast Medical Center in Fountain Valley, CA, told MNT he found this study’s findings interesting.

“We also see changes in taste in patients who lose weight from surgery, so it was not surprising,” Ali said. “What was hard to determine for me (was) whether it’s the actual medication causing the change in taste or whether it’s the weight loss. So that’s something that would be interesting to see if it’s the medication itself affecting taste.”

“And a majority of taste is also smell so is it really the smell that’s being affected or is it the taste buds that are changing — how is this mechanism really working to affect somebody’s taste?” he added.

While a person’s improved taste sensation may make healthy foods more tasty, Ali said on the flip side it can also possibly make foods you shouldn’t be eating taste better as well.

“Kids and babies tend to eat stuff that adults don’t really find tasteful because their sense of taste is different, and that changes with time. [Through] exposure to lots of things throughout life, your sense of taste changes. So perhaps if your taste is improving, you might find it easier to eat healthier foods.”

— Mir Ali, MD, board certified bariatric surgeon