Evidence that within each person, smell sensitivity varies over the course of each day

A person’s ability to smell may vary throughout the day in accordance with their circadian rhythm, according to new evidence in a small study by Brown University researchers who are looking at how sleep may influence eating patterns in teens.

“This finding is very important for olfactory perception science,” said Rachel Herz, lead author of the study in Chemical Senses and an adjunct assistant professor of psychiatry and human behavior at the Warren Alpert Medical School of Brown University. “This hadn’t been known before and this is the first clear, direct evidence.”

As one of the five senses, smell is an important ability, Herz noted, not only for experiencing and enjoying the world, but also for receiving information about danger, such as nearby fire or spoiled food, and for basic functions like eating. Changes in the sense during the day can affect all these capabilities.

Source: Smell sensitivity varies with circadian rhythm, study suggests