Most of us have noticed how a scent can trigger a memory, perhaps of your mother’s apple pie or an uncle’s cigar at family celebrations. Now scientists have found that sleeping with a scent diffuser in the room each night demonstrably improved memory and neural functioning.
Researchers at the University of California, Irvine, randomly assigned adults aged 60 – 85 to an ‘Olfactory Enriched’ or Control group. The Enriched group were exposed to a different scent each night for two hours, using a scent diffuser. Individuals in the control group had the same experience with a miniscule amount that was too small to notice. Neuropsychological assessments and fMRI scans were administered at the beginning of the study and after 6 months.
The results were astonishing! ‘A statistically significant 226% improvement was observed in the enriched group compared to the control group on the Rey Auditory Verbal Learning Test and improved functioning was observed in the left unicate fasciculus (a part of the brain that connects different areas widely) as assessed by mean diffusivity.’
The study concluded: ‘Minimal olfactory enrichment administered at night produced improvements in both cognitive and neural functioning. Thus, olfactory enrichment may provide an effective and low-effort pathway to improved brain health.’
“It’s an important first step in showing how very simple odour enrichment can influence or at least protect against degeneration,” said Leslie Kay, a professor of psychology and neuroscience at the University of Chicago, who was not involved in the study.
It’s worth reading the whole article: https://www.frontiersin.org/articles/10.3389/fnins.2023.1200448/full