A soft device inserted in the nose to cut an individual’s ability to smell may lead to significant reduction in body weight and a loss of appetite for fattening foods, according to the results of a pilot study presented here at the European Congress on Obesity (ECO) 2018.
The device, which will be marketed under the name NozNoz (Beck Medical), is a wearable nasal insert that inhibits an individual’s sense of smell without affecting the ability to breath.
It is designed to fit the anatomy of the nose and act as a physical barrier, changing airflow in the nose by directing it into the lower respiratory tract and thus bypassing the olfactory system.
Likened to a nasal “contact lens,” the device is designed to be worn up to 12 hours a day and then disposed of after 2 weeks. It will be marketed as a wellness, not medical, device and will be available direct to consumers.
In the current study of 65 obese adults, researchers found that those who wore the device while eating a hypocaloric diet had significant reductions in weight and body mass index (BMI) compared with controls. In addition, they also significantly reduced their consumption of sweet foods and beverages and showed a reduction in insulin levels.
Speaking at a press conference, study presenter Dror Dicker, MD, Hasharon Hospital, Rabin Medical Center, Petah Tikva, Israel, said that the device “is one of the solutions we can use” to help combat obesity.
He added: “It’s not a medication, it’s very easy to use, and it helps the lifestyle intervention to lose weight and not to regain [it].”
Session co-chair Gabriella Segal Lieberman, MD, head of the Israeli Center for Weight Management at the Sheba Medical Center, Tel HaShomer, Ramat Gan, Israel, who was not involved in the study, told Medscape Medical News that “olfaction is important in weight management.”
She said, “It’s much more important in rodents than it is humans beings, but I think it’s important in human beings and it’s interesting to explore that field.” However, she pointed out that the control in the trial, which consisted of daily saline drops in the nose, “was not really a control group…and I was wondering if just sticking something up your nose wouldn’t affect things other than smelling.”
Segal Lieberman also cautioned against overinterpreting the findings. “The bottom line is important. If you lose weight with a device and lose less weight without it, that’s impressive in itself…. But if you’re talking about mechanisms and you’re trying to imply that the mechanism is via affecting the olfactory system, I’m not sure that this study is really proving that. It’s more like a proof of concept.”
Benefit Only in Younger Patients
During his presentation, Dicker explained that addressing obesity via olfaction is plausible given previous data. For example, studies have shown that food odors and an individual’s sense of smell can significantly influence how much they eat and their dietary preference. Moreover, olfaction is linked to hormonal and peptide expression, while leptin, insulin, and ghrelin levels have affected olfactory sensitivity.
Dicker also pointed out that being overweight or obese has been linked to altered sensitivity to smells and higher appetite stimulation upon exposure to food odors.
The researchers therefore sought to determine whether using the nasal insert could not only reduce an individual’s sense of smell but also reduce their body weight, alter their dietary preferences, and improve metabolic dysfunction.
They recruited individuals aged 18 to 65 years who had a BMI of 30 to 43 kg/m2. Participants were excluded if they were pregnant or had diabetes, high blood pressure, thyroid dysfunction, or other medical conditions.
After a brief run-in period, the participants were randomly assigned to the device group or the control group, who put saline drops in their nose. Participants in the device group were instructed to wear the nasal device in both nostrils every day for 5 to 12 hours a day.
Both groups were assigned to a hypocaloric diet, which reduced their intake by 500 kcal per day, and were required to keep a food diary. Participants also completed an eating preferences and habits questionnaire, in addition to which blood samples were taken at baseline and at the final visit, from which cholesterol, triglyceride, glucose, and insulin levels were determined. The researchers also used the samples to calculate insulin resistance by using homeostatic model assessment.
The device and control groups were well matched, with a mean baseline BMI of approximately 36 kg/m2 and a mean age of 50 to 52 years. Fifty-seven percent of the participants were male.
A total of 65 individuals competed the study, including 37 in the device group and 28 in the control group. The nasal device significantly decreased individuals’ ability to smell (P < .001), with no difference in change in olfaction among those in the control group.
Overall, both groups lost weight during the study, with no significant difference between the two groups after 14 weeks, at a mean weight reduction of 6.6% in the device group and 5.65% in the control group.
However, Dicker pointed out that previous studies have shown that olfaction declines with age, typically starting around 50 years of age. When the researchers restricted their analysis to the 29 participants age 50 years or younger, they found that the device was associated with significantly greater weight loss (7.7% vs 4.0%; P < .01).
These changes were accompanied by significant reductions in BMI among individuals aged 50 years or younger, from a mean of 35.9 kg/m2 to 33.1 kg/m2in the device group vs 36.5 kg/m2 to 35.0 kg/m2 in the control group (P < .01).
Surprisingly, the team saw that, across all ages, the device was associated with significantly less sugar consumption (P = .015), less artificial sweetener consumption (P = .02), and reduced consumption of sweet beverages (P = .001) compared with the control group.
In each comparison, the decrease was greater among individuals age 50 years or younger using the device, who also consumed significantly fewer alcoholic beverages than control participants (P = .000).
Participants in the device group also had significant reductions in insulin levels over baseline (P = .015), which was not seen in the control group. There was a trend for a difference in insulin change between the two groups (P = .08).
Dicker told the press conference that they are not sure how exactly the device works, “but we just opened a window to an area that wasn’t really researched.” He said that they would like to follow up with functional MRI studies, but they hypothesize that, by blunting olfaction, they are blunting the effect of hormones on appetite.
Dicker told Medscape Medical News that the device was highly acceptable to patients. He said it was “easy to persuade” the participants to try the device “because obese patients want to lose weight, but we had a percentage of dropout like every other obesity trial [of] around 50%”.
However, he pointed out that only 16% dropped out because of the device itself, with the remaining dropouts related to follow-up and visits.
Beck Medical Funded the study. Adva Beck is the entrepreneur and main shareholder in Beck Medical Ltd. Elhanan Greenberg serves as advisory to Beck Medical, E.N.T Head and Neck Surgery Specialist, and is a shareholder.
European Congress on Obesity (ECO) 2018. Abstract O8.2. Presented May 25, 2018.
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