What Is It?
A silvery evergreen shrub that originated in the Mediterranean region and is now grown worldwide, rosemary (Rosmarinus officinalis) is prized both as a culinary and healing herb. Many of the current uses of this aromatic plant have been handed down from ancient times.
Historically, Greek and Chinese healers used rosemary as a soothing digestive aid and to relieve intestinal gas (flatulence). In many countries today, rosemary leaf tea is a standard treatment for these purposes. Germany’s Commission E, for instance, has even given its official approval to rosemary leaf tea for treating indigestion, gas, bloating, and other digestive symptoms. The tea can be prepared from dried rosemary leaves; alternatively, small amounts of either the tincture or the liquid extract can be mixed with warm water.
The ancient Greeks also believed that the plant could enhance memory, and students were known to take their examinations wearing garlands of rosemary. In Shakespeare’s Hamlet, Ophelia in her mad scene lists rosemary among the herbs she’s wearing: “There’s rosemary, that’s for remembrance.”
The herb’s enduring reputation as a memory aid may in part be due to its high concentrations of health-promoting antioxidants. These compounds help to protect the brain and other parts of the body against unstable oxygen molecules, called free radicals, which can damage cells in the body. Rosemary may also sharpen memory by helping to prevent the breakdown of a brain chemical called acetylcholine.
Inhalation use: Today, aromatherapists commonly recommend inhaling rosemary oil for sharpening the mind, countering mental fatigue, and treating nervous exhaustion. The essential oil of rosemary can be inhaled directly, added to bath water, or diluted with a neutral carrier oil and used for massage.
Topical use: Rosemary oil, which is steam-distilled from the plant’s pale blue flowers, may help soothe muscle sprains, strains, and arthritic joints. The oil contains camphor, a skin irritant that can increase blood circulation to the skin when applied topically. The aromatic oil is frequently added to hair preparations. One recent trial found that rosemary oil, when combined with thyme, cedarwood, and lavender oils in a neutral carrier oil (jojoba) may help to lessen a type of patchy hair loss of unknown cause called alopecia areata.
Internal use: Rosemary oil is one of the four essential oils recently made available in capsule form for internal use. Herbalists often suggest capsules containing rosemary oil along with the essential oils of oregano and thyme for the treatment of yeast (Candida) overgrowth in the intestines. This blend is used in part because of rosemary’s apparent antibacterial and antifungal properties.
There are no known drug or nutrient interactions associated with rosemary.
Only take rosemary oil internally in the form of an enteric-coated capsule. When taken in any other form, it can irritate the stomach and cause heartburn.
When applied topically, rosemary oil can cause dermatitis and skin redness in people who are sensitive to it. If this happens to you, stop using the herb.
If you are pregnant, don’t use rosemary in therapeutic amounts. High doses could potentially cause complications. The amounts that typically appear in food or cosmetics pose no risk, however.
If you have epilepsy, don’t take medicinal amounts of rosemary; the camphor in the herb could potentially aggravate seizures.
If insomnia is a problem, don’t take a rosemary bath in the evening; its stimulant effect may keep you from falling asleep.
David Edelberg, MD