Quick Hits
Daily brief research updates from the cognitive sciences

aroma smell brain cognitive performance aging

Who would have thought it – well, who apart from aromatherapists that is.

I have reported multiple times on the benefits of exercise on cognitive performance but also on diet, sleep, and cognitive activity. Many of these are well know and tie in to general health advice. However there is little research and thought given to smells, aromas.

Smell may also be an underrated sense – offices, for example, and homes, often give careful consideration to lighting but little thought to smell – though some smart marketeers and retail establishments have given some considerable thought to this e.g. the appealing smell of a new car, the smell of fresh bread in a supermarket all support the brand experience and encourage customers to buy more.

We could and would also assume that smell would have some, mostly emotional effect on us in certain circumstances – if a room is particularly bad smelling it would have a negative impact on work performance. However this piece of research showed that mere exposure, while asleep nonetheless, had dramatic impacts on cognitive performance (a 226% increase no less!) and also helping “grow” the brain in those with olfactory impairment.

These results are more than impressive – so impressive that I immediately became sceptical and read the academic paper to check on the validity – all above board I can report.

The study involved participants (this was partly disrupted by the pandemic) – 46 in total split into an intervention group and a control group. The active study group used an aroma diffuser over a six-month period and cycled through 7 different aromas. This diffuser was only active for two hours each night.

When the participants were re-measured on cognitive ability at the end of the study period there was a 226% increase in cognitive ability (the average of multiple assessments).

This is impressive. However, we do know we have a direct connection between our sense of smell and memory and we also know that there have been over 70 mental disorders that are related to loss of smell – not just COVID. We also know that aroma enhancement – consciously focusing on and being exposed to different aromas – improves well being.

Further research has also shown multiple benefits in the brain with aroma enhancement linked to growth in various areas of the brain including the hippocampus which is closely related to memory.

This all points to aroma and our sense of smell being an important and vastly underestimated sense but also an effective intervention strategy – and in this case one that is particularly easy to implement: aroma diffuser in the bedroom is as easy as it gets.

I have to say that this research opened my eyes, well my nostrils, and it’s high time to plug in the aroma diffuser sitting dustily in the corner of my living room.

Andy Habermacher

Andy Habermacher

Andy is author of leading brains Review, Neuroleadership, and multiple other books. He has been intensively involved in writing and research into neuroleadership and is considered one of Europe’s leading experts. He is also a well-known public speaker, speaking on the brain and human behaviour.

Andy is also a masters athlete (middle distance running) and competes regularly at international competitions (and holds a few national records in his age category).

twitter / LinkedIn


Cynthia C. Woo, Blake Miranda, Mithra Sathishkumar, Farideh Dehkordi-Vakil, Michael A. Yassa, Michael Leon.
Overnight olfactory enrichment using an odorant diffuser improves memory and modifies the uncinate fasciculus in older adults.
Frontiers in Neuroscience, 2023; 17
DOI: 10.3389/fnins.2023.1200448

More Quick Hits