Rosemary, derived from the Latin word rosmarinus meaning “dew of the sea,” has long been known for its healing and cognitive benefits, seemingly helping with everything from hair loss to memory lapses.
The Mediterranean herb has been associated with memory for thousands of years, as evident in Shakespeare’s Ophelia where the eponymous character described various herbs and their powers: “There’s rosemary, that’s for remembrance…” (Hamlet, Act IV, Scene 5)
But can rosemary actually improve memory, or is it merely folk medicine?
There’s a small but growing body of research that has found the smell of rosemary can actually stimulate your memory, improve your mood, and make you more alert and accurate.
In one study, a team of scientists at University of Northumbria (United Kingdom) assessed the olfactory impact of rosemary and lavender essential oils on cognitive performance and mood in a group of volunteers. The volunteers were placed in cubicles infused with one of the two scents (or none at all) and given a series of memory- and attention-based tasks.
The study found that rosemary greatly enhanced memory and alertness while lavender impaired their working memory and their reaction times to tasks. (Not surprising, since lavender is often associated with calmness and sleep.)
Another study by the same team of scientists looked specifically at the effects of 1,8-cineole, a volatile chemical compound in the oil that gives rosemary its pungent aroma. The compound works in much the same way as the drugs used to treat dementia: it increases a chief neurotransmitter called acetylcholine, which assists in learning, memory, and arousal.
Volunteers were exposed to varying amounts of 1,8-cineole while asked to complete certain mental tasks. The study found that the more 1,8-cineole they inhaled, the faster and more accurate they were on the cognitive tests.
(The chemical compound is not unique to rosemary, by the way — it’s also found in other highly aromatic plants like bay, sage, and eucalyptus. These plants release their fragrant oils to deter herbivores and attract the predators of herbivores.)
If you’re wondering how simply smelling something can have that type of effect on the brain, it turns out that inhalation is one of the best ways of getting drugs into the brain. (You might remember the post I wrote about Mycobacterium vaccae, or “nature’s Prozac.”)
When you eat a drug, it gets broken down in the liver (which processes everything absorbed by the gut) but when you inhale it, small molecules pass into the bloodstream and make their way to the brain without being broken down first. Blood samples from the volunteers confirmed this, as the scientists found traces of 1,8-cineole and other compounds from rosemary oil in their blood.
More recently, the University of Northumbria researchers conducted a similar study with children, and found that the scent of rosemary significantly enhanced their working memory.
How and why it works is still largely unknown, and eating rosemary does not seem to have the same effect on the brain. But, these findings indicate rosemary essential oil could have potential as a straightforward and cost-effective solution to improving academic performance in children, as well as workplace performance in adults.
There have been other peer-reviewed studies on the physiological effects of rosemary oil on the human body, and more findings that suggest the scent of rosemary can reduce stress and anxiety (leading to increased concentration and better performance).
This is not to say you should be sniffing rosemary all day every day (how much and how often for optimal benefit is still to be determined), but if there’s a chance rosemary can make you smarter… why not grow some rosemary in a pot by the window, or rub a few sprigs of fresh rosemary when you feel like you’re lacking focus?
And if fresh rosemary isn’t available, running a diffuser with a few drops of rosemary essential oil would have the same brain-boosting benefits. (Not to mention your home will smell amazing.)