In an article from July 2023 in the Frontiers in Neuroscience a study is described that examined the effects of overnight olfactory enrichment on cognitive abilities in older adults. In the study, 43 participants aged between 60 and 85 years old were divided into two groups: an Olfactory Enriched group and a Control group. The Olfactory Enriched group was exposed to seven different odorants over the course of a week, with one distinct odorant per night for two hours using an odorant diffuser. The scents used in the study was rose, orange, eucalyptus, lemon, peppermint, rosemary, and lavender. These essential oils were chosen because they represent different odor groups: resinous, flowery, fruity, and aromatic. The Control group had a similar experience but with minimal amounts of the odorants.
The Results
Neuropsychological assessments and fMRI scans were conducted at the start of the study and after six months. The results indicated a significant 226% improvement in memory for the Olfactory Enriched group as measured by the Rey Auditory Verbal Learning Test. Furthermore, there was observed improvement in the functioning of the left uncinate fasciculus, an area of the brain associated with memory and learning, as assessed by mean diffusivity—a measure used in MRI to detect the integrity of white matter tracts in the brain. This is what other researchers comment about the study:
"It's an important first step in showing how very simple odor enrichment can influence or at least protect against degeneration." - Leslie Kay, professor of psychology and neuroscience at the University of Chicago
Conclusion
The conclusion drawn from this study was that minimal olfactory enrichment during nighttime could lead to improvements in cognitive and neural functions, presenting a low-effort and effective method for enhancing brain health in older adults.
This innovative approach leverages the known connection between olfaction and memory and may provide a simple at-home treatment for cognitive decline, which is a growing concern in aging societies. The study offers a promising direction for further research into non-pharmacological interventions to support cognitive health in the elderly.
"The findings are quite sensational, but the fact that the sense of smell is linked to dementia is not new.”- Geir Sælbæk Norwegian National Centre for Ageing and Health
For a detailed understanding of the methodology and the findings, you can read the full study on the Frontiers in Neuroscience website.
