Reducing food intake generally has a direct correlation with weight loss. But for many people, weight-loss programs fail because it’s difficult to ignore hunger when their body communicates that feeling to the brain.
A new intervention may help fix the problem by literally freezing the nerve that communicates hunger signals to the brain — and results so far have been promising.
In the study, participants had a needle inserted into their back. Using live imaging, an interventional radiologist targeted the nerve in question (the posterior vagal trunk) and froze it using argon gas.
Researchers said all 10 subjects in the study saw positive results — decreased appetite, a feeling of being more full, and, ultimately, weight loss.
The findings are being presented today at the Society of Interventional Radiology’s 2018 Annual Scientific Meeting.
The research was funded by HealthTronics, a company that manufactures the ablation probes used in the treatment.
The research also hasn’t been published yet in a peer-reviewed journal.
However, an expert interviewed by Healthline said the research shows promise as well as provides a new means of treatment by targeting nerves.
“I think, from my perspective, this research and this experiment really fits into the broader domain of neuromodulation,” said Dr. Michael Knopp, professor of radiology, Novartis Chair of Imaging Research, and director of the Wright Center of Innovation in Biomedical Imaging at The Ohio State University Wexner Medical Center.
“It’s just using a different way — freezing — instead of, for example, electrical stimulation, to modify the signals that are being carried forward to the brain,” Knopp told Healthline.
“Now, the key thing is which pathway is being targeted and whether this is a pathway that can show effects. I think from that regard, their finding is quite consistent with some of the neuromodulation efforts that have been done by multiple teams.”
Knopp says that neuromodulation is often used clinically to suppress tremors in people with Parkinson’s disease.
“Fundamentally, the team at Emory has taken a very reasonable approach, and it’s quite impressive that they were able to show the findings that they did,” Knopp said.
Disrupting the hunger signal
“The impetus behind this was to find something in the body that’s feeding back to the brain and causing people to quit their weight loss programs, and seeing if we could interrupt that,” Dr. David Prologo, an interventional radiologist from Emory University School of Medicine and lead author of the study, told Healthline.
Prologo explained that as an interventional radiologist, he’s well-versed in percutaneous (through the skin) procedures to freeze nerves as a means to stop pain signals.
“So we wanted to bring these two things together, thinking of how we can overcome diet attrition and how we can quiet the body’s response to calorie restrictions,” he said.
“This ability to reach nerves, freeze them, and shut them down in interventional radiology came together as this study.”
Unlike gastric bypass surgery, which is typically performed on people who are classified as morbidly obese, the nerve-freezing intervention targets a population that isn’t morbidly obese, but still have trouble losing weight.
“People who undergo these other interventions — gastric bypass surgery and so forth — are morbidly obese or extremely obese patients with a body mass index (BMI) greater than 40,” explained Prologo. “Our target population is BMI 30 to 37, which is overweight and mildly or moderately obese, but not severely obese, and not qualifying for these other interventions. So our target population sort of lives in no man’s land.”
Prologo said that the overall safety of the study, as well as participants reporting feeling less hungry, were both expected by his research team. But one of their findings came as somewhat of a surprise.
“What we did not expect, and did not predict, to be honest, was a second report we were getting from the subjects, and that’s that they were getting fuller faster,” he said.
“So ultimately, what happened in our pilot cohort were two changes: patients getting fuller faster and being less hungry.”
Interventions involving the modification of nerve signals are an intriguing frontier when it comes to treating various ailments.
“We are collectively striving for very targeted therapies along a known or identified neurofunctional pathway to basically get a very specific signal changed — in this case, with the team from Emory, the hunger signal — to support the resolution of the ailment or the change in the physiological behavior,” said Knopp.
While the researchers at Emory found positive results, Prologo acknowledged the small sample size of the preliminary safety and feasibility study, and said that a larger clinical trial is in the works.
While he values the academic credibility of the study first and foremost, Prologo would also like to see this research affect societal change.
“I’d like to add this. This is sort of a blow against fat-shaming. This is something that’s important to me, a passion of mine,” he said.
“I’ve watched so many people who have a disease — obesity — get shamed and get condescended to and belittled because they can’t overcome their disease with their mind. To me, this is totally ridiculous. We don’t do this with any other disease.
“I think interrupting a signal from the body back to the brain should prove to those folks, the fat-shamers, that this inability to lose weight using a calorie restriction program is something real that originates in the body, and not a weakness of the mind,” he concluded.