A new study found that a simple fragrance diffusion could strengthen the memory of older adults and deter dementia. The findings provide a new perspective on the link between smell and memory, according to the researchers.
For the study by the University of California, Irvine (UCI) neuroscientists, diffused different aromas for two hours every night for six months in older adults' bedrooms. The findings showed that there was a 226% increase in cognitive capacity. The participants were between the ages of 60 and 85 and showed no memory impairments, according to UCI’s press statement. The research was published in the journal Frontiers of Neuroscience.
The participants were given a diffuser along with seven cartridges, each containing a different natural oil. Those in the control group received the same oils, but a significantly small amount. They were asked to use different cartridges every night and release the scent for two hours as they slept.
After all seven cartridges were used, a word list test was commonly used to evaluate memory. Furthermore, brain imaging showed better integrity in the brain pathway which connects the medial temporal lobe and the decision-making prefrontal cortex, which weakens with age. The participants also reported that they slept better, according to the statement.
Loss of the ability to smell is known to be a predictor of about 70 neurological and psychiatric diseases including include Alzheimer’s and other dementias, Parkinson’s, schizophrenia as well as alcoholism. Last month, a study by researchers at the University of Chicago showed that people who carry the gene variant APOE e4, linked with an increased risk for Alzheimer’s disease, could lose their sense of smell first, signalling Alzheimer’s disease.
Moreover, a 2022 study published in the journal Dementia suggested that exposure to different smells could be an effective non-pharmacological intervention for people with dementia and considered for future research. With the new study, researchers are tapping into this knowledge and turning it into a non-invasive method to deter dementia.
“By making it possible for people to experience the odours while sleeping, we eliminated the need to set aside time for this during waking hours every day,” the study’s first author, and project scientist Cynthia Woo said in the statement. The use of odours to boost memory is an emerging intervention in dementia care and warrants further attention.