Fragrance can boost cognitive capacity among older adults by 226 percent, University of California–Irvine (UCI) researchers announced in newly published study findings on Aug. 1.
During the study, fragrance was wafted through the bedrooms of 43 older adults for two hours every night for six months, and researchers claim that in doing so participants’ memories “skyrocketed.”
Such findings, researchers said, tie smell and memory into an “easy, non-invasive technique” for strengthening memory and potentially deterring dementia.
“[Smell] has the special privilege of being directly connected to the brain’s memory circuits,” professor Michael Yassa, a researcher and chair of the university’s Center for the Neurobiology of Learning and Memory, said in a statement. “Everyone has experienced how powerful aromas are in evoking recollections, even from very long ago.”
The study, which was funded by Procter and Gamble, involved men and women aged 60 to 85 who didn’t have memory impairment. All of the participants were given a scent diffuser and seven cartridges, each containing a different natural oil.
Some of them received full-strength cartridges, while others were given the oils in tiny amounts. Each participant put a different cartridge into their diffuser each evening prior to going to bed, and the diffuser activated for two hours as they slept.
According to the study report, those participants who received the full-strength cartridges had a 226 percent increase in cognitive performance compared to those who didn’t.
Cognitive testing was performed using a word list test that’s commonly used to evaluate memory. Brain imaging conducted during the study also revealed “better integrity” in brain pathways that weaken with age, and such participants also reported sleeping more soundly.
According to scientists who were involved in the study, the loss of smell can contribute to more than 70 neurologic and psychiatric diseases— including Alzheimer’s, Parkinson’s, schizophrenia, and alcoholism—and emerging data suggests a link between smell loss because of COVID-19 and the ensuing decreases in cognition.
The new study was based on previous research that found that exposing people with moderate dementia to about 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 reality is that over the age of 60, [sense of smell] and cognition starts to fall off a cliff,” said Michael Leon, a UCI professor of neurobiology and behavior who was involved in the research. “But it’s not realistic to think people with cognitive impairment could open, sniff and close 80 odorant bottles daily. This would be difficult even for those without dementia.”
According to researchers, the study was conducted while participants were asleep in order to eliminate the need for them to set aside hours for it during their waking time.
The research team would next like to study the effect of scents on those with diagnosed cognitive loss, in the hope that such research will lead to more investigations into smell therapies for memory impairment.
A product based on the study and designed for people to use at home is expected to be sold commercially this fall.
