Energy deprivation can affect olfactory sensitivity for food odours.

Olfactory sensitivity for food and non-food odours was not related to either fasting or to ghrelin levels.

Women had higher olfactory sensitivity than men.

Sex differences were related to olfactory sensitivity through adiponectin levels.

Energy deprivation as well as hormones that regulate appetite and eating can influence olfactory function. This study investigated olfactory sensitivity for a food-related and a non-food odour prior to and after a meal, and its relationship to the energy-regulating hormones ghrelin and adiponectin.

The olfactory sensitivity for orange and rose (PEA) odour in healthy, normal-weight volunteers (19 women, 45 men, 1 undisclosed individual) was not affected by the consumption of a meal. Olfactory sensitivity was not associated with concentrations of circulating ghrelin. However, olfactory sensitivity was higher for women than for men, indicating better olfactory performance. This difference between women and men was related to concentrations of plasma adiponectin, an adipose-specific hormone.

Adiponectin may thus explain why sex differences in olfactory sensitivity emerge, and may also account for some of the inconsistencies in previous findings on sex differences. Our findings add to the limited literature on the impact of stomach and adipose tissue-derived hormones on olfactory sensitivity. Further studies are needed to establish a causal link between circulating adiponectin and a sex difference in olfactory sensitivity.

Odour threshold

Ghrelin

Gut hormones

Food restriction

Fasting

The raw data on which this manuscript is based can be accessed on OSF: https://osf.io/qvcwf/

© 2022 The Author(s). Published by Elsevier Inc.