Among the senses we cherish, the sense of smell is frequently overlooked – yet the appropriate aromas might be precisely what your brain requires to stay active as you age.

Scientists at the University of California, Irvine, have found compelling evidence that enhancing the air with scents enhances cognitive performance by fortifying a crucial connection between neurological regions related to memory and decision-making.

Their study, which included 43 individuals between the ages of 60 and 85, indicates that cognitive decline and conditions like dementia could potentially be decelerated by merely diffusing a variety of fragrances in the bedroom before bedtime each night.

Sustaining mental activity as we grow older is crucial for preserving cognitive well-being. This goes beyond solving the daily crossword puzzle; it involves surrounding ourselves with a variety of sights and sounds to engage the brain.

Studies have demonstrated that enhancing the environment with scents promotes neuroplasticity in other animals, particularly in experiments involving animals exhibiting symptoms similar to neurological disorders in humans, as outlined in this study.

It’s reasonable to consider that humans might gain advantages from encountering a diverse ‘scent-scape’. From a physiological perspective, our capacity to sense smells diminishes before the onset of cognitive decline. The decline in this sense also coincides with a reduction in brain cells, suggesting a robust link between the sense of smell and neurological function.

The olfactory sense has the special privilege of being directly connected to the brain’s memory circuits, said neurobiologist Michael Yassa when the results were revealed in August.

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.

To assess the potential for saving cognitive decline through sensory stimulation, Yassa and his team supplied 20 participants in the study with a variety of natural oils infused with scents of rose, orange, eucalyptus, lemon, peppermint, rosemary, and lavender.

The remaining participants received a ‘sham’ containing minimal amounts of an odorant. Each participant, regardless of group, had to use one of the oils with a diffuser to scent their home for two hours every night, rotating through the array of fragrances over a six-month duration.

A series of neuropsychological assessments were subsequently employed to evaluate the participants’ memory, verbal learning, planning, and attention-switching abilities before and after the six-month trial.

Remarkably, there was a notable 226 percent contrast in the responses between those exposed to a range of fragrances and individuals in the control group. Furthermore, a brain scan unveiled a significant alteration in the connections between crucial brain areas related to memory and cognition within the test group.

Given that all volunteers had comparable mental health, the researchers now intend to investigate whether the findings remain consistent for individuals already diagnosed with some level of cognitive impairment.

Regardless of age or mental state, engaging your sense of smell when the lights go out and silence descends is a rather pleasant way to stimulate the mind before bedtime.

The findings from this study are documented in Frontiers in Neuroscience.

This article’s initial version was released in August 2023