Studies Investigate How Your Nose Might Be a Pathway to Improved Memory

The technical term is “olfactory stimulation” or “olfactory enrichment.” In lay terms, it refers to using different smells to stimulate the brain, with a hope and goal that it might improve memory. The National Institutes of Health (NIH) says a decrease in ones’ ability to smell (known as olfactory loss) occurs in 5 to 15% of the population and impacts quality of life and safety. The NIH says there are also more associations being seen between loss of smell and neurodegenerative diseases such as Parkinson’s, as well as findings related to COVID-19 infection, which involved loss of smell for many. On the plus side, in 2023 a study published in the journal Frontiers in Neuroscience showed a strong association between exposure to new odors, such as from essential oils, and improved memory. Memory and cognitive tests and MRI brain imaging found that memory and cognitive skills improved by more than 200% in the tested group compared to the controls that had no olfactory enrichment. Other earlier studies have found olfactory enrichment improved verbal fluency in Parkinson’s disease, improved puzzle solving skills, decreased depression symptoms, and improved cognition in people with early dementia. Another benefit can be improved sleep. One speculated reason for these effects is that the olfactory nerve is the only sensory nerve that goes directly to the brain’s limbic system, where memories are made and stored. An ear, nose and throat surgeon was quoted as saying when this limbic system is exposed to new odors, brain cells make new connections in what’s called brain plasticity. (A somewhat similar intervention is aromatherapy, which also uses essential oils and which the NIH says can be used to improve mental and physical health. It is distinct from olfactory enrichment. For now, olfactory enrichment is available only in clinical research trials.)