New research from UC Irvine determines nightly aromatherapy improves cognitive capacity by 226% for older adults.
We’ve all had experiences where a distinct smell—perhaps a whiff of salty beach air, freshly baked bread, or a campfire—floods our brain with vivid memories. That’s because your olfactory system (AKA your sense of smell) is directly connected to your brain’s memory circuits.
For decades, scientists have studied the brain’s ability to trigger powerful memories. But can the simple act of smelling improve brain health and possibly prevent dementia?
A group of neuroscientists at the University of California, Irvine think so.
A new study found that when fragrances wafted through the bedrooms of older adults as they slept, their memories improved by a whopping 226%. The findings, published in Frontiers in Neuroscience, could be the basis for a simple, non-invasive treatment for memory loss.
In this article, we’ll unpack the full story behind the study and what it means for the future of cognitive health.
Simple Fragrances Produce a Profound Memory Boost
The study involved men and women between the ages of 60 and 85 without memory impairment. Researchers gave these participants scent diffusers and seven scent cartridges, each containing a different essential oil. (Participants in a control group were also given diffusers, but only received tiny amounts of the scented oils).
The participants were instructed to place a different cartridge in their diffuser each night before going to bed, which activated for two hours as they slept—a process known as “olfactory enrichment.”
After six months of nightly aromatherapy, the participants took the Rey Auditory Verbal Learning Test (RAVLT), which is widely used to evaluate verbal learning and memory.
The results were staggering: The participants in the enrichment group showed a 226% improvement in cognitive performance compared to the control group.
Further, fMRI scans showed that olfactory enrichment literally changed the participants’ brains. The scans revealed better integrity in the left uncinate fasciculus, a brain pathway that connects the medial temporal lobe to the decision-making prefrontal cortex.
“To my knowledge, that level of improvement is far greater than anything that has been reported for healthy older adults,” says Dr. Micahel Leon, Ph.D., Professor Emeritus in the Department of Neurobiology at UC Irvine.
These findings beg an important question: How does the simple act of smelling fragrances improve your memory to such a large degree?
How Does Aromatherapy Improve Memory?
The health of the human brain depends on having sufficient odor stimulation. But as people age, their sense of smell and cognitive capacity decline significantly.
Scientists have long observed that losing the ability to smell can predict the development of many neurological and psychiatric diseases including Alzheimer’s, Parkinson’s, schizophrenia, and even alcoholism. However, the underlying mechanism is still largely a mystery.
“The olfactory system is the only sense to have a direct ‘superhighway’ access to the memory centers of the brain,” explains Dr. Leon. “The other senses can contribute to the health of the memory centers, but they have to take the brain’s ‘side streets’ to get there and consequently have much less impact on the health of those centers.”
Past studies have found that exposing patients with moderate dementia to up to 40 different odors twice a day boosted their memories, improved their language skills, and alleviated depression. However, the UCI team isn’t confident that people with cognitive health issues can open, sniff, and close that many scents every day.
“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,” project scientist Cynthia Woo told Science Daily. “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.”
More research is necessary to determine whether olfactory enrichment can become a standard method to prevent cognitive loss, but the early findings are promising.
The Future of Aromatherapy for Cognitive Health
Given how simple the UCI’s project was, people are curious what the next steps are to introduce this method to a wider audience.
For starters, the team wants to study the technique’s impact on people with diagnosed cognitive loss. The researchers also say they hope their findings will inspire more investigations into olfactory therapies for cognitive impairment.
But perhaps the most exciting news of all is that the team has plans to release a consumer-facing device that replicates the technique used in their study. The device, called Memory Air, releases 40 odors sequentially while you sleep. It’s expected to be released in January 2024.
This may just be the first “whiff” of success, but the potential for an easy, drug-free, non-invasive therapy to strengthen memory is great news for researchers and patients alike.