Aromas against Alzheimer's disease
Scientists have long known that the loss of olfactory capacity, or ability to smell, can predict development of nearly 70 neurological and psychiatric diseases. These include Alzheimer's and other dementias, Parkinson's, schizophrenia and alcoholism. Evidence is emerging about a link between smell loss due to COVID and ensuing cognitive decrease. Researchers have previously found that exposing people with moderate dementia to up to 40 different odors twice a day over a period of time boosted their memories and language skills, eased depression and improved their olfactory capacities. The UCI team decided to try turning this knowledge into an easy and non-invasive dementia-fighting tool.
In a new study published in Frontiers in Neuroscience, when a fragrance wafted through the bedrooms of older adults for two hours every night for six months, memories skyrocketed. Participants in this study by University of California, Irvine neuroscientists reaped a 226% increase in cognitive capacity compared to the control group. The researchers say the finding transforms the long-known tie between smell and memory into an easy, non-invasive technique for strengthening memory and potentially deterring dementia.
The project was conducted through the UCI Center for the Neurobiology of Learning & Memory. It involved men and women aged 60 to 85 without memory impairment. All were given a diffuser and seven cartridges, each containing a single and different natural oil. People in the enriched group received full-strength cartridges. Control group participants were given the oils in tiny amounts. Participants put a different cartridge into their diffuser each evening prior to going to bed, and it activated for two hours as they slept.
People in the enriched group showed a 226% increase in cognitive performance compared to the control group, as measured by a word list test commonly used to evaluate memory. Imaging revealed better integrity in the brain pathway called the left uncinate fasciculus.