Michael Leon, who led a 2023 study on smell and memory published in Frontiers in Neuroscience, told USA Today that your sense of smell has a “direct superhighway into the memory centers of the brain and consequently has a far greater impact (on memory) than those other senses (sight and sound).”
The small but interesting study involved 43 healthy female and male volunteers, aged between 60 and 85. One half of the participants were exposed to seven different odors (rose, orange, eucalyptus, lemon, peppermint, rosemary, and lavender) broken down to one a week, using an odor diffuser, for two hours every night for four months. The other half had diffusers with no scent. After brain scans and verbal memory tests, the researchers found that the volunteers who were exposed to different scents while they slept performed 226% better on the verbal memory tests and also showed better function in the neural connections related to memory (via USA Today). A 2022 study done on people with dementia saw a similar boost in memory.
Although the exposure to different scents was done while the volunteers slept in the 2023 study, the principle of introducing new smells to your nose to boost brain health can be practiced when you’re awake, according to the researchers. Leon shared (via National Public Radio) that we are deprived of new and different smells in general, and brain exercises of this nature can have both short-term and long-term benefits for memory.