Human olfactory sensitivity varies across geographical locations

It has been assumed that olfactory sensitivity is relatively consistent in different populations worldwide. Emerging, yet fragmented evidence lends credit to the hypothesis that olfactory sensitivity may be geographically diverse. To gain deeper insight regarding the interplay between geographical, demographic, and health factors in the context of olfactory sensitivity, we conducted a multicenter study comprising data from 1046 participants inhabiting 19 locations around the world. Our results revealed that location accounted for 17–20% of the variance in chemosensory sensitivity. Demographic and psychological factors related to working memory and depressive symptoms also contribute to explaining sensitivity to odors, accounting for 1.6–2.9% of the variance in chemosensory sensitivity. Thus, we conclude that inhabitants of different geographical regions may present different sensitivities to chemical stimuli. We discuss the factors that could potentially be included in future investigations to pinpoint even more precisely what factors determine differences in chemosensory sensitivity around the globe.