Rosemary boosts brains

The culinary herb rosemary does wonderful things for a leg of lamb but it is much more than a garnish. Today rosemary is worn as a symbol of remembrance and historically it has been credited with many healing and mystical properties. Now in a recent encounter with this well-travelled herb, scientists believe they have proven it can significantly improve brain function.

The name “rosemary” derives from the Latin ros meaning dew, and marinus meaning sea, hence one of its common names is “dew of the sea”. Whatever you call it, this herb has been revered by cultures throughout history.

In ancient Greece rosemary was burnt at shrines to drive away evil spirits and illnesses. It was believed that a fresh twig beneath your pillow could ward off nightmares. A necklace made from rosemary was also believed to preserve your youth and growing rosemary was thought to attract elves to your garden.

Throughout Europe during the Middle Ages rosemary was one of the herbs used to flavour beer and wine. In Spain and Italy it was considered a safeguard against witches and evil influences generally. The Sicilians believed that young fairies, taking the form of snakes, would lie among its branches. Across the world it has also had a reputation for enhancing memory which is why we still use as an emblem of remembrance.

The evidence is quite strong this belief in rosemary’s effect on memory has a strong basis in fact.

One of the main components of the essential oil contained in rosemary is 1,8-cineole. It is the aroma of rosemary that is held to impact memory so researchers tested this by exposing subjects to varying levels of rosemary essential oil aroma and then measuring blood levels of 1,8-cineole. The subjects were then given tests to measure the speed and accuracy of their cognitive function.

The higher the concentration of 1,8-cineole in the blood, the greater the speed and accuracy for all subjects. The fact that both speed and accuracy improved showed that overall cognitive function was improved by exposure to rosemary aroma and that there was no “trade off” between speed and accuracy.

This may all be happening because of 1,8-cineole which is a “terpene” and is fat soluble. It can be inhaled and enter the bloodstream via the nasal or lung mucosa and since it is fat soluble can cross the blood-brain barrier into the brain. Previous research has shown that 1,8-cineole will stop the breakdown of the brain neurotransmitter acetylcholine.

Although less pronounced the aroma also had an effect on mood. People were more content when smelling rosemary than when not smelling it but interestingly, lower levels of 1,8-cineole in the blood corresponded to greater contentment than higher levels. This suggests that the mechanism for altering mood is different to that for improving cognitive performance. The findings also suggest that contentment relates to improved mental performance but “arousal” does not.

Whether or not rosemary attracts elves remains to be proven but in the meantime you can rest assured that it will give your brain a boost.