Smelling Rosemary Boosts Intelligence

Researchers from the University of Northumbria, UK, has discovered that one of the oils which gives rosemary its pungent scent improves speed and accuracy when performing certain mental tasks.

Rosemary has a long history as a traditional remedy with such widespread uses as a hair rinse and a cat repellent.  It has also long been thought to boost brain power, so scientists were not totally surprised that respondents performed better in tests.  However, they were shocked when they realised the rosemary oil has an effect on the blood, it was reported in the Therapeutic Advances in Psychopharmacology journal.

Dr. Mark Moss, who devised and wrote the study, was interested in rosemary’s fragrant aroma, which has long been cherished by chefs and bakers. Could the 1,8-cineole, a constituent part of rosemary oil, be detected in the bloodstream after exposure to just the aroma?

According to the author's abstract:

Here we show for the first time that performance on cognitive tasks is significantly related to concentration of absorbed 1,8-cineole following exposure to rosemary aroma, with improved performance at higher concentrations. Furthermore, these effects were found for speed and accuracy outcomes, indicating that the relationship is not describing a speed–accuracy trade off. The relationships between 1,8-cineole levels and mood were less pronounced, but did reveal a significant negative correlation between change in contentment and plasma 1,8-cineole levels. 

Conclusion: These findings suggest that compounds absorbed from rosemary aroma affect cognition and subjective state independently through different neurochemical pathways.

An upcoming study with rosemary will aim to determine whether 1,8-cineole, when ingested orally, can survive the rigors of the gastrointestinal system to be similarly absorbed into the bloodstream.
The potential benefits of the research are wide-ranging.

‘Plants are very complex organisms and contain many different active compounds and these vary in concentration from plant to plant and even within the same plant over the course of a day,’ Dr Moss told msnbc.com.

‘The accumulation of knowledge regarding possible impacts of plant aromas and extracts could potentially lead to an identification of the best combination to promote specific effects.’
‘At its grandest conclusion might be the development of plant-based drugs that might extend mental capacity into old age through pharmacological challenge to decline,’ Moss concludes.