Int J Med Sci 2018; 15(3):269-273. doi:10.7150/ijms.21528
Olfactory stimulation modulates the blood glucose level in rats
1. The First Department of Oral and Maxillofacial Surgery, Graduate School of Dentistry, Osaka University, Osaka 565-0871, Japan.
2. Department of Health and Nutrition, Faculty of Health Science, Kio University, Nara 635-0832, Japan.
Tsuji T, Tanaka S, Bakhshishayan S, Kogo M, Yamamoto T. Olfactory stimulation modulates the blood glucose level in rats. Int J Med Sci 2018; 15(3):269-273. doi:10.7150/ijms.21528. Available from http://www.medsci.org/v15p0269.htm
In both humans and animals, chemosensory stimuli, including odors and tastes, induce a variety of physiologic and mental responses related to energy homeostasis, such as glucose kinetics. The present study examined the importance of olfactory function in glucose kinetics following ingestion behavior in a simplified experimental scenario. We applied a conventional glucose tolerance test to rats with and without olfactory function and analyzed subsequent blood glucose (BG) curves in detail. The loss of olfactory input due to experimental damage to the olfactory mucosa induced a marked decrease in the area under the BG curve. Exposure to grapefruit odor and its main component, limonene, both of which activate the sympathetic nerves, before glucose loading also greatly depressed the BG curve. Pre-loading exposure to lavender odor, a parasympathetic activator, stabilized the BG level. These results suggest that olfactory function is important for proper glucose kinetics after glucose intake and that certain fragrances could be utilized as tools for controlling BG levels.
Keywords: blood glucose, odor, glucose tolerance test, the area under the curve of blood glucose