Study Finds Diffusing Scents While Sleeping May Boost Brain Health

About two out of three Americans have some level of cognitive impairment at an age 70, according to the National Institutes of Health. Cognitive decline takes a tremendous toll on the quality of life of an individual and breaks the heats of family members. It also can be quite costly with expensive medications and hospitalizations.

Currently, cognitive decline is not preventable or curable, but there are some tactics you can take to protect your brain health. Harvard Health recommends:

• Exercising regularly
• Eating a Mediterranean-style diet
• Limiting alcohol
• Getting seven to eight hours of sleep
• Engaging in mentally stimulating activities
• Staying in touch with social contacts

University of California at Irvine (UCI) neuroscientists also believe that being exposed to scents while sleeping may improve memory and modify the uncinate fasciculus, according to a study published in Frontiers in Neurology.

The uncinate fasciculus is a part of the brain that’s not completely understood. What is known that it’s part of the limbic system, the part of the brain involved in behavioral and emotional responses, and it plays a critical role in emotions and memory and may be involved in the formation and retrieval of episodic memories.

The study, conducted through UCI Center for the Neurobiology of Learning & Memory, involved 43 healthy men and women without cognitive impairment between the ages of 60 and 85 recruited from a list of interested adults. Participants were given neuropsychological assessments and fMRI scans before being randomly assigned to an olfactory enriched group or control group.

Participants in the olfactory enriched group with exposed to seven different odorants a week, one per night for two hours using an odorant diffuser for six months. Participants in the control group had the same regimen but with minute amounts of scents. This was followed by another set of neuropsychological assessments and fMRI scans six months after the study. Results showed that when compared to the control group, the olfactory enrichment group had:

• 226 percent improvement on the Rey Auditory Verbal Learning Test
• Improved functioning in the left uncinate fasciculus
• Better memories

“It’s a very small study, so more research is needed,” says Bernard Kaminetsky, MD, medical director, MDVIP. “However, I like this study because it gives older adults another tool to help protect their brains. And it makes sense that the olfactory senses are involved, as a lack of olfactory senses can foretell the development of neurological conditions such as Alzheimer's disease and Parkinson’s disease.”

Diffusers have become popular in recent years. The natural oil scents used in the study were:

• Rose
• Orange
• Eucalyptus
• Lemon
• Peppermint
• Rosemary
• Lavender

Researchers did not use multiple scents at one time. They recommend this practice overnight to avoid the need to set aside time during the day.

For more brain health resources, check out MDVIP’s Brain Resource Center »