Rosemary (Rosmarinus officinalis) is an evergreen shrub with needle-like leaves and a woody aroma. Though best known as a food seasoning, it is also one of the most popular aromatic and medicinal plants used around the world. It has been hailed since ancient times for its medicinal properties, and was traditionally used to help alleviate muscle pain, improve memory, boost the immune and circulatory system, and promote hair growth.
In ancient Greece and Rome, rosemary was thought to strengthen memory, and interestingly, research indicates that inhaling rosemary oil helps prevent the breakdown of acetylcholine, a brain chemical important for thinking, concentration and memory. When 20 young adults were asked math questions in a small room diffused with rosemary oil, their speed and accuracy increased in direct proportion to the duration that the oil was diffused. Additionally, their blood levels of certain rosemary compounds likewise increased—revealing that rosemary can enter your body through breathing alone. Similarly, nursing students who breathed rosemary oil while taking a test reported increased concentration and information recall compared to breathing lavender oil or no essential oil at all. Other research suggests that breathing rosemary and other essential oils may improve brain function in older adults with dementia, including those with Alzheimer’s disease.
In folk medicine, rosemary is utilized as a mild pain reliever. In a two-week study, stroke survivors with shoulder pain who received a rosemary oil blend with acupressure for 20 minutes twice daily experienced a 30% reduction in pain. Those who received only acupressure had a 15% reduction in pain. Additionally, an animal study determined that rosemary oil was slightly more effective for pain than acetaminophen, a common over-the-counter pain medication.
Some studies suggest that rosemary may also be effective at reducing stress. When nursing students breathed rosemary oil from an inhaler before and during a test, their pulse decreased by about 9%—while no significant change occurred without rosemary oil. Because increased pulse rates reflect short-term stress and anxiety, rosemary oil may naturally reduce stress. Additionally, when 22 young adults sniffed rosemary oil for 5 minutes, their saliva had 23% lower levels of the stress hormone cortisol compared to those who smelled a non-aromatic compound. Increased cortisol levels can suppress your immune system, contribute to insomnia and cause mood swings, among other potential problems.
In one study, a woman with Raynaud’s disease—which impairs circulation— massaged her hands with a rosemary oil blend, finding that it helped warm her fingers more than a neutral oil. These effects were confirmed by thermal imaging. Rosemary oil may help by expanding your blood vessels, thereby warming your blood so that it circulates throughout your body more easily.
Another study suggests that rosemary oil may help reduce tissue inflammation that can lead to swelling, pain and stiffness. It may do so by stemming the migration of white blood cells to injured tissues to release inflammatory chemicals. When people with rheumatoid arthritis were given 15-minute knee massages using a rosemary oil blend three times weekly, they had a 50% decrease in inflammatory knee pain in two weeks, compared to a 12% decrease in those not given the oil.
Rosemary oil also has antioxidant and anti-inflammatory effects, which test-tube studies suggest may fight cancer cells. Certain animal studies also indicate that rosemary oil may stimulate the release of bile, which is important in fat digestion, and activate your own antioxidant defense mechanisms to protect your liver.A flavorful and aromatic plant often used in culinary dishes, rosemary is also a potent medicinal herb. It has been used for centuries for its diverse healing properties, and modern science appears to confirm what people have known throughout history. Whether using it in the kitchen or as a medicinal supplement, rosemary is a safe, effective, and powerful herb to include in your diet.