Do people who can’t smell really breathe differently?
By Stephanie Feuer
A new study from the Olfaction Research Group at the Weizmann Institute of Science in Rehovot published in the journal, Nature Communications, suggests just that.
Unlike previous studies based on single exposure smell tests, this research tracked breathing patterns for a full 24 hours as people went about their daily lives. The research team equipped two groups with special devices to monitor their nose-breathing - 31 people with self-reported normal smell ability and 21 people who were born without a sense of smell (congenital anosmics).
While both groups breathed at similar rates, the people with normal smell ability took about 240 extra "sniffs" per hour while awake. The scientists also conducted a follow-up experiment. They put people with normal smell abilities in a completely scent-free room and tracked their breathing. When there were no smells around, these people started breathing in patterns similar to the congenital anosmics.
The researchers concluded that people born without a sense of smell have different patterns of breathing while awake and when asleep, and suggest that “a portion of the deleterious outcomes associated with anosmia may be attributed to altered patterns of respiratory nasal airflow rather than a direct result of lost odor perception per se.”
As detailed in excellent articles in Scientific American and Popular Science, this new research raises many unanswered questions, most notably if people with acquired anosmia would exhibit these same respiratory patterns; how retronasal smell figures into this breathing pattern, and of course what would be seen in a larger sample size. The conclusion about breathing patterns contributing to the negative impacts of anosmia are not necessarily supported by the research, especially given that many of the health and quality of life issues reported with anosmia are reported by those who have acquired this condition.
Nevertheless, the techniques used for measurement represent a breakthrough in olfactory research and with the paucity of research on congenital anosmia, any insights are welcome.
