By John Salak –
There is a new kind of smell test and it just may get a passing grade when it comes to improving the memory of older adults.
The University of California-Irvine reports that mature adults who were exposed to specific fragrances for two hours every day for six months reported a whopping 226 percent increase in cognitive capacity, including memory, compared to those who didn’t get a sniff.
The results underscore the link between a robust olfactory capacity and the ability to stave off dozens of 70 neurological and psychiatric diseases. The UC-Irvine researchers note that their findings may lead to an easy, non-invasive technique for strengthening memory and potentially deterring dementia.
The study 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 before going to bed and it activated for two hours as they slept.
People in the enriched group showed a 226 percent 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. Participants also reported sleeping more soundly.
The results are potentially significant in several ways. The findings could help the approximately 20 percent of all adults and more specifically the 26 percent of older adults who told a University of California, Los Angeles poll that they have poor memories. The research could also help offset the numerous reported neurological and psychiatric problems that develop in older adults as they lose their ability to smell. These problems can include Alzheimer’s and other dementias, Parkinson’s, schizophrenia and alcoholism.
Earlier research had reported that exposing people with moderate dementia to up to 40 different odors twice a day over time helped boost their memories and language skills, eased depression and improved their olfactory capacities. The UC-Irvine team took this initial research further by working to develop an easy and non-invasive dementia-fighting tool.
“The reality is that over the age of 60, the olfactory sense and cognition starts to fall off a cliff,” said Michael Leon, a UC-Irvine professor. “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.”
This led the team to find a cleaner smell-oriented support system. “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,” explained the study’s first author, project scientist Cynthia Woo. “By making it possible for people to experience the odors while sleeping, we eliminated the need to set aside time for this during waking hours every day.”
The initial findings have also cleared the way for new research focused on people with diagnosed cognitive loss, while possibly leading to the development of new olfactory therapies for memory impairment.
“The olfactory sense has the special privilege of being directly connected to the brain’s memory circuits,” explained Michael Yassa, professor and James L. McGaugh Chair in the Neurobiology of Learning & Memory at the university. “All the other senses are routed first through the thalamus. 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.”
