Nasal device that impedes smell can spur weight loss, curb sugar craving
A nasal device that reduces the ability to smell can lead to weight loss and changes in dietary preference for sweet food in adults younger than 50 years with obesity, suggesting a novel approach to managing obesity, according to a pilot study presented at the recent European Congress on Obesity (ECO) in Vienna, Austria.
“Obese people have a greater stimulation of appetite when exposed to food odours,” explained lead author Dr Dror Dicker of Hasharon Hospital Rabin Medical Center in Petah Tikva, Israel. The researchers therefore sought to study the effects on body weight by deliberately reducing the ability to smell.
In a pilot study, 65 adults with obesity were randomized to wearing a soft silicone nasal insert for 5–12 hours daily (n=37) or a control group who self-administered two drops of saline in each nostril daily. Participants were given a diet with a 500 kcal/day deficit from their regular diet and were followed up every two weeks. [ECO 2018, abstract O8.2]
The nasal device significantly reduces olfactory sensitivity from baseline (p<0.001), indicating that the device worked as expected; whereas saline drops had no effect on olfaction.
While all participants lost weight with no significant difference between the device and control arms in the entire population, weight loss was significantly greater with the device than with saline control (7.7 percent vs 4.1 percent; p<0.02) among participants from the subgroup aged <50 years in a stratified analysis prespecified by age.
Furthermore, participants in the device arm had significantly reduced dietary preferences for sugar, sweet beverages, and artificial sweeteners compared with the control arm in the <50 age subgroup, but this was not seen in the subgroup older than 50 years.
Similarly, systolic blood pressure was significantly reduced with the device in the subgroup aged <50 years (-16.5 vs -4.2 mm Hg; p=0.03) but not in the subgroup ≥50 years.
Insulin levels also trended towards a reduction with the device vs control (-1.7 vs 2.0; p=0.069) among participants aged <50 years, but not in those older than 50 years.
“This novel smell-reducing self-administered nasal device caused weight loss and reduced dietary preference for sweet food in subjects aged <50 years,” concluded Dicker and co-authors. “Further studies should be conducted to explore this new option and to determine the role of this device for treatment of obesity and diabetes.”