Turns out, the nose really does know!
According to recent research conducted at the University of California, Irvine (UCI), neuroscientists have discovered a straightforward method of diffusing fragrances that significantly enhances memory in older adults.
The study’s findings show that tapping into the connection between smell and memory could potentially offer a solution to help slow down cognitive decline and even prevent the risk of dementia.
The study, conducted by the UCI Center for the Neurobiology of Learning & Memory, involved participants aged between 60 and 85 years old with no memory issues.
The participants were separated into two groups, enriched and control, and over a 6-month period were exposed to different fragrances every night for two hours while they slept.
Those in the enriched group had diffusers with full-strength scent cartridges, while those in the control group were given the same scents but in reduced quantities.
At the conclusion of their study, researchers found that those in the enriched group showed a whopping 226 per cent increase in cognitive performance compared to the control group.
Brain imaging taken from the enriched group showed better connectivity in the left uncinate fasciculus, a pathway between brain regions responsible for decision-making and the perception of scents, an area known to weaken with age.
“The olfactory sense has the special privilege of being directly connected to the brain’s memory circuits,” study co-author Professor Michael Yassa said.
“Everyone has experienced how powerful aromas are in evoking recollections, even from very long ago. However, unlike with vision changes that we treat with glasses and hearing aids for hearing impairment, there has been no intervention for the loss of smell.”
According to the National Institute of Health, not being able to identify scents is a “hallmark early symptom and predictor of several neurological disorders” like Alzheimer’s. So being able to enhance the left uncinate fasciculus with odour-evoked tests is a promising solution for accessible and non-invasive tools for fighting dementia.
“The reality is that over the age of 60, the olfactory sense and cognition starts to fall off a cliff,” said Michael Leon, professor of neurobiology and behaviour and a CNLM fellow.
“But it’s not realistic to think people with cognitive impairment could open, sniff and close 80 odourant bottles daily. This would be difficult even for those without dementia.”
“That’s why we reduced the number of scents to just seven, exposing participants to just one each time, rather than the multiple aromas used simultaneously in previous research projects,” noted study first author Cynthia Woo.
“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.”