Scent of Rosemary Enhances and Improves Brain's Cognitive Performance

Rosemary, Rosmarinus officinalis, is a woody, perennial herb with fragrant, evergreen, needle-like leaves and white, pink, purple or blue flowers. The plant is native to the Mediterranean region and is a member of the mint family Lamiaceae. It is one of two species in the genus Rosmarinus, the other species being Rosmarinus eriocalyx, which is native to northwest Africa and southern Spain.

Hailed since ancient times for its medicinal properties, there is still a lot to learn about the effects of rosemary. Now researchers writing in Therapeutic Advances in Psychopharmacology, published by SAGE, have shown for the first time that blood levels of a rosemary oil component correlate with improved cognitive performance.

Rosemary (Rosmarinus officinalis) is one of many traditional medicinal plants that yield essential oils. But exactly how such plants affect human behaviour is still unclear. Mark Moss and Lorraine Oliver, working at the Brain, Performance and Nutrition Research Centre at Northumbria University, UK designed an experiment to investigate the pharmacology of 1,8-cineole (1,3,3-trimethyl-2-oxabicyclo[2,2,2]octane), one of rosemary's main chemical components.

The investigators tested cognitive performance and mood in a cohort of 20 subjects, who were exposed to varying levels of the rosemary aroma. Using blood samples to detect the amount of 1,8-cineole participants had absorbed, the researchers applied speed and accuracy tests, and mood assessments, to judge the rosemary oil's affects.

Video: Harvesting Rosemary for Distillation

Results indicate for the first time in human subjects that concentration of 1,8-cineole in the blood is related to an individual's cognitive performance – with higher concentrations resulting in improved performance. Both speed and accuracy were improved, suggesting that the relationship is not describing a speed–accuracy trade off.

Meanwhile, although less pronounced, the chemical also had an effect on mood. However, this was a negative correlation between changes in contentment levels and blood levels of 1,8-cineole, which is particularly interesting because it suggests that compounds given off by the rosemary essential oil affect subjective state and cognitive performance through different neurochemical pathways. The oil did not appear to improve attention or alertness, however.

Terpenes like 1,8-cineole can enter the blood stream via the nasal or lung mucosa. As small, fat-soluble organic molecules, terpenes can easily cross the blood–brain barrier. Volatile 1,8-cineole is found in many aromatic plants, including eucalyptus, bay, wormwood and sage in addition to rosemary, and has already been the subject of a number of studies, including research that suggests it inhibits acetylcholinesterase (AChE) and butyrylcholinesterase enzymes, important in brain and central nervous system neurochemistry: rosemary components may prevent the breakdown of the neurotransmitter acetylcholine.

"Only contentedness possessed a significant relationship with 1,8-cineole levels, and interestingly to some of the cognitive performance outcomes, leading to the intriguing proposal that positive mood can improve performance whereas aroused mood cannot," said Moss.

Typically comprising 35-45% by volume of rosemary essential oil, 1,8-cineole may possess direct pharmacological properties. However, it is also possible that detected blood levels simply serve as a marker for relative levels of other active compounds present in rosemary oil, such as rosmarinic acid and ursolic acid, which are present at much lower concentrations.

In addition to its mild camphoraceous, uplifting aroma, the natural compounds in Rosemary oil contain strong cleansing properties, making it ideal for anyone concerned with immune system health. NOW Rosemary Oil is team-distilled.Gas Chromatography/Infra-red Spectroscopy verifiedSuggested Use For aromatherapy use. For all other uses, carefully dilute with a carrier oil such as jojoba, grapeseed, olive, or almond oil prior to use. Please consult an essential oil book or other professional reference source for suggested dilution ratios.Warnings Natural oils are highly concentrated and should be used with care.Always dilute before any use other than aromatherapy. Keep out of reach of children. Avoid contact with eyes. If pregnant or lactating, consult a practitioner before use.

Quantum Day

25 February 2012

Scent of Rosemary Enhances and Improves Brain's Cognitive Performance