Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany; IFB AdiposityDiseases, Leipzig University Medical Center, Philipp-Rosenthal-Str. 27, 04103, Leipzig, Germany.
Department of Neurology, Max Planck Institute for Human Cognitive and Brain Sciences, Stephanstraße 1a, 04103, Leipzig, Germany; Montreal Neurological Institute, McGill University, 3801 University Street, Montreal, QC, H3A 2B4, Canada.
Appetite. 2022 Jan 1;168:105774. doi: 10.1016/j.appet.2021.105774. Epub 2021 Oct 29.
Smell perception plays a role in eating behavior and might be involved in the development of obesity. In fact, olfactory function is impaired in obesity and might depend on metabolic health factors. To date, the underlying neural mechanisms remain unclear. Here, we investigate neural processing of food-related odors in normal-weight, overweight and obese individuals. Fifty-three young and healthy participants (28.8 ± 4.4 years, 27 female; 24 normal-weight, 10 overweight, and 19 obese) were presented with high- (chocolate, potato chips) and low-caloric (orange, cucumber) food odors during a functional magnetic resonance imaging (fMRI). We also assessed olfactory identification ability, body mass index (BMI), body fat percentage, insulin resistance, and leptin levels. In brief, olfactory perception of food odors was linked to brain activity in the entorhinal and piriform cortex, and the insula, hippocampus, and amygdala. Insulin resistance was negatively related to olfactory identification. Additionally, perception of sweet versus savory odors was related to a higher brain activity in the right middle/superior frontal gyrus. Finally, we found no effect of obesity status, BMI, metabolic factors, or body fat percentage on neural responses to food odors. Overall, this suggests that food odor processing might depend on factors other than body weight status or associated markers of metabolic health.
嗅觉感知在饮食行为中起着作用，并且可能与肥胖的发展有关。事实上，肥胖会损害嗅觉功能，并且可能取决于代谢健康因素。迄今为止，其潜在的神经机制尚不清楚。在这里，我们研究了正常体重、超重和肥胖个体对与食物相关的气味的神经处理。53 名年轻健康的参与者（28.8±4.4 岁，女性 27 名；正常体重 24 名，超重 10 名，肥胖 19 名）在功能磁共振成像（fMRI）期间接受了高热量（巧克力、薯片）和低热量（橙子、黄瓜）食物气味的刺激。我们还评估了嗅觉识别能力、体重指数（BMI）、体脂肪百分比、胰岛素抵抗和瘦素水平。简而言之，食物气味的嗅觉感知与内嗅皮层和梨状皮层以及脑岛、海马和杏仁核的大脑活动有关。胰岛素抵抗与嗅觉识别呈负相关。此外，与甜与咸气味的感知与右中/额上回的大脑活动更高有关。最后，我们没有发现肥胖状态、BMI、代谢因素或体脂肪百分比对食物气味神经反应的影响。总的来说，这表明食物气味处理可能取决于体重状况或代谢健康相关标志物以外的因素。
