You don’t have to obsessively complete numerous crossword puzzles each day to improve your memory and cognitive abilities.

All you have to do is sniff something, according to a new British study.

There’s a certain type of scent that can help you think more clearly—and the best part is, it’s a scent that is pleasant and easy to find.

Read on to find out which sort of smell provides this neurological lift through the nose…


The new study was designed to show whether breathing in something called 1,8-cineole—a chemical compound found in rosemary oil—would have an effect on mental abilities. The researchers suspected that it might boost mental abilities because past research has shown that 1,8-cineole might slow the breakdown of acetylcholine, a neurotransmitter that’s essential for both memory and many other mental processes including recognizing sequences and performing quick mathematical tasks.

Twenty male and female volunteers, average age about 23, were selected. One at a time, they were asked to sit in an office. After the office door was closed, a device hidden under a bench in the office diffused four drops of rosemary oil into the air. The amount was enough for participants to smell it but not so strong that they would suspect that the odor was part of the study. Participants sat in the office and did nothing for anywhere from four to 10 minutes. Researchers varied the amount of time spent in the office so that each participant would breathe in a different amount of the oil.

Several minutes later, each participant was given three mental tests. The tests involved the ability to subtract from numbers flashing on a computer screen and to detect sequences in numbers that scrolled across the screen.

After the mental tests, researchers measured participants’ blood for levels of 1,8-cineole and then compared these levels with the mental test results.

The comparison strongly suggested that the rosemary aroma helped participants’ performance—the more rosemary oil that participants had absorbed into their blood streams, the better those participants performed on the three mental tests, on average.


To learn more about how smelling rosemary oil might boost the brain, I phoned the lead author of the study, Mark Moss, PhD, head of the department of psychology at Northumbria University in England.

Dr. Moss told me that he’s not sure how long the cognitive boost might last after sniffing the oil.

So I asked Dr. Moss the big question—should we all buy rosemary oil to smell, especially before working on an important or difficult mental task? His answer—“It’s too early to say that rosemary oil will definitely help, but it could possibly help—and there are no risks associated with the aroma.”

Rosemary oil is available online and in health-food stores and vitamin stores. Prices vary but average about $5 to $8 an ounce. The researchers used a brand called Tisserand Rosemary Organic essential oil (, $12.50 for 0.32 oz). You can buy a device that lets you diffuse the aroma into the air, and Dr. Moss suggests diffusing four drops for a pleasant but not overpowering aroma. But you don’t have to use a diffuser—just drip four drops onto a cotton ball. Then place the diffuser or the cotton ball somewhere in the room that you’re in, ideally a few feet away, so the smell isn’t too intense and doesn’t give you a headache or make you feel nauseated.