Optimal Being

Participants who smelled odors while they slept performed better on word-recall tests. Smell is probably our most underappreciated sense. “If you ask people which sense they would be most willing to give up, it would be the olfactory system,” says Michael Leon, a neurobiologist at the University of California, Irvine. But a loss of smell has been linked to health complications such as  depression  and cognitive decline. And mounting evidence shows that olfactory training, which involves deliberately smelling strong scents on a regular basis, may help stave off that decline. Now a team of researchers led by Leon has successfully boosted cognitive performance by exposing people to smells while they sleep. Twenty participants—all older than 60 years and generally healthy—received six months of overnight olfactory enrichment, and all significantly improved their ability to recall lists of words compared with a control group. The study appeared in  Frontiers in Neuroscien...

People over 60 who inhale essential oils of eucalyptus, rosemary or lavender, for example, improve their memory at night. They can better remember what they just heard. For 6 months, neurologists at the University of California at Irvine had 20 people over 60 sleep while an aroma diffuser in their bedroom diffused essential oils for 2 hours. The researchers had the diffuser filled with a different aroma every day of the week. The researchers used essential oils from roses, oranges, eucalyptus, limes, peppermint, rosemary and lavender. During the same period, 23 over-60s in a control group fell asleep every night while a diffuser in their bedroom diffused no detectable essential oils. Before and after the 6-month experimental period, the researchers tested the mental abilities of the subjects with a battery of tests. Results Overall, the researchers found no statistically significant changes in the test results. [Table] However, there was one exception: on the Rey Auditory Verbal Le...