Experts recommend regular physical activity, a healthy diet and better sleep to minimize memory loss in old age. But what if a basic pleasure like smelling a fragrance during sleep can boost your memory? Researchers from the University of California, Irvine, make an interesting finding in their latest study.

The study, published in the Frontiers in Neuroscience, suggests that infusing aroma in the bedrooms of older adults for two hours each night results in significant improvements in their memory.

"The olfactory sense has the special privilege of being directly connected to the brain's memory circuits. All the other senses are routed first through the thalamus. Everyone has experienced how powerful aromas are in evoking recollections, even from very long ago. However, unlike with vision changes that we treat with glasses and hearing aids for hearing impairment, there has been no intervention for the loss of smell," said Michael Yassa, a neurologist and co-author of the study.

The study evaluated 43 participants aged 60 to 85 without any memory impairment. Each participant was provided a diffuser, along with seven distinct cartridges, each with a unique natural oil. The participants in the enriched group were given full-strength cartridges, while those in the control group got tiny amounts of the oils. All the participants were asked to insert a different cartridge into their diffuser each night, which then operated for two hours while they slept.

After six months, people in the enriched group had a 226% surge in cognitive performance compared to the control group. This enhancement was measured using a standard word list test used for evaluating memory.

Brain imaging showed marked integrity in their neural pathway, which often weakens with age. This pathway, known as the left uncinate fasciculus, facilitates communication between the medial temporal lobe and the prefrontal cortex, which is crucial for decision-making. The participants also observed an improvement in their sleep quality.

Previous studies have shown that loss of smell can predict the development of nearly 70 neurological and psychiatric diseases, including Alzheimer's, Parkinson's, schizophrenia and alcoholism. When people with moderate dementia inhaled around 40 distinct odors on two separate occasions each day, they exhibited heightened memory and language abilities. It also helped them to alleviate depression and enhance their sense of smell.

"The reality is that over the age of 60, the olfactory sense and cognition start to fall off a cliff. 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," co-author Michael Leon said, explaining why they limited the number of scents to seven in the latest study.

The next step for the team involves evaluating the effects of the olfactory technique on people with diagnosed cognitive decline. Researchers believe the findings will pave the way for further exploration into olfactory-based treatments for memory impairment.