Exposure to certain fragrances during sleep could boost memory, finds study

By India Today Health Desk: In the realm of sensory indulgence, our sense of scent often remains overlooked and underappreciated. Yet, the right aromas hold the power to awaken our ageing brains and keep them buzzing with vitality.

A study, published in Frontiers in Neuroscience, by the University of California, Irvine, has unveiled compelling evidence that infusing the air with delightful fragrances can enhance cognitive performance by boosting the connection between memory and decision-making centres in the brain.

The experiment involved a group of 43 individuals aged 60 to 85, revealing that diffusing different scents in the bedroom before sleeping each night could potentially slow cognitive decline and conditions like dementia.

All were given a diffuser and seven cartridges, each containing a single and different natural oil. People in the enriched group received full-strength cartridges. Control group participants were given the oils in tiny amounts.

Participants put a different cartridge into their diffuser each evening prior to going to bed, and it activated for two hours as they slept.

Nurturing our ageing grey matter is paramount to preserving cognitive health and extends beyond the daily crossword puzzle.

It entails sprinkling our surroundings with an array of captivating sights and sounds for our brains to savour.
People in the enriched group showed a 226% increase in cognitive performance compared to the control group, as measured by a word list test commonly used to evaluate memory.

In the animal kingdom, introducing stimulating odours to the environment has been shown to foster neuroplasticity, particularly in creatures that exhibit symptoms similar to human neurological disorders.

It is not far-fetched to believe that humans could also reap the benefits of a rich and complex "scent-scape". Physiologically, our ability to detect smells begins to fade before our cognitive abilities wane.

The loss of this sense is accompanied by a decline in brain cells, indicating a profound link between scent and neurological function.

Scientists have long known that the loss of olfactory capacity, or the ability to smell, can predict the development of nearly 70 neurological and psychiatric diseases. These include Alzheimer’s and other dementias, Parkinson’s, schizophrenia and alcoholism.

"The reality is that over the age of 60, the olfactory sense and cognition starts to fall off a cliff," said Michael Leon, professor of neurobiology & behaviour and a CNLM fellow. "But it’s not realistic to think people with cognitive impairment could open, sniff and close 80 odorant bottles daily. This would be difficult even for those without dementia."

Neurobiologist Michael Yassa describes the olfactory sense (the sense of smell detects and discriminates odours as well as social cues which influence our innate responses) as having a direct connection to the brain's memory circuits, unlike the other senses that pass through the thalamus first.