Rosemary (Rosmarinus officinalis) is native to the Mediterranean region, where the ancient Greeks revered it for stimulating the brain and assisting memory. The name Rosmarinus literally means “dew of the sea”, an apt name for a coastal plant dedicated to Venus or Aphrodite, the goddess of love who arose from the sea. It is a conifer-like shrub with intensely aromatic, evergreen foliage and pale-blue flowers.
Dioscorides wrote of rosemary: “the eating of its flower in a preserve comforts the brain, the heart and the stomach; sharpens understanding, restores lost memory, awakens the mind and in sum is a healthy remedy for various cold ailments of the head and the stomach.”
Rosemary has been traditionally associated with memory and fidelity and has featured in both weddings and funerals since ancient Egyptian times.
Active ingredients
Rosemary has many biologically active components, including essential oils, the major ones being cineole, pinene, camphor, borneol and carvacrol. The plant also contains diterpenes, flavones, the caffeic acid derivative rosmarinic acid and the triterpene ursolic acid. The diterpenes carnosol and carnosic acid are the major antioxidant components.
Using rosemary
Improving cognitive performance
There have been a few studies on humans using rosemary. A couple of interesting ones showed that, when testing 140 healthy young adults, the inhalation of rosemary oil enhanced the feeling of alertness and cognitive functions as evaluated using the Cognitive Drug Research (CDR) test battery.
In a separate study, the aroma of rosemary oil increased performance in exam students while increasing free-radical scavenging activity and reducing cortisol, showing it not only improved their results but also helped to relieve the accompanying stress.
In Australia, a randomised, placebo-controlled, double-blind, crossover study was conducted to investigate possible acute effects of dried rosemary leaf powder on cognitive performance in elderly people. There was a biphasic dose-dependent effect in measures of speed of memory: the lowest dose (750mg) of rosemary had a statistically significant beneficial effect compared with placebo, whereas the highest dose (6000mg) had a significant impairing effect. The conclusion showed that rosemary had the most positive effect on cognitive performance in the doses closest to normal food consumption — consumed regularly over a long term.
Reading these, rosemary is not only effective for memory and cognition in the elderly — on whom most of the research has been done — but can also help younger people, particularly when they need it, such as around exam time. Maybe we all should be consuming it regularly or using the oil in a burner for memory improvement.
Anti-Alzheimer’s disease
Rosemary can potentially be used regularly as a shampoo for a mild Alzheimer’s preventative. The theory behind this is the aromatic essential oils could be absorbed transdermally (through the skin), making their way into the circulation and to the brain. Studies were conducted to compare rosemary shampoo to the pharmaceutical tacrine for Alzheimer’s disease. Tacrine is a potent inhibitor of the enzyme acetylcholinesterase, which inhibits the breakdown of the neurotransmitter acetylcholine — a key factor in memory and learning. Tacrine preserves brain levels of acetylcholine.
Rosemary contains at least a dozen such inhibitors and therefore is likely to have a positive effect.
Anti-inflammatory
Common drugs called COX-2 inhibitors (cyclo-oxygenase-2) are major anti-inflammatories. These are marketed for many conditions, including Alzheimer’s prevention and pain relief, although they do have potentially risky side-effects. Rosemary has several natural COX-2 inhibitors in apigenin, carvacrol and ursolic acid, without the potential risks.
Acne
Propionibacteria are key pathogens in the development and progression of the chronic inflammatory skin disease, acne. Rosemary, as a wash, significantly suppresses the expression of pro-inflammatory cytokines in acne and inhibits many of the inflammatory pathways that cause an ongoing problem with this condition.
Antibacterial, antiviral, antifungal
Essential oils, including the ones high in rosemary, are known for their antiseptic — antibacterial, antiviral and antifungal — activities. In food they are used as preservatives and medicinally they have been shown to be antimicrobial, analgaesic, sedative and anti-inflammatory.
Antioxidant
The antioxidant activity of spices, herbs and their extracts is attributed to the phenolic components, with which rosemary is plentifully endowed.
Anticancer
Rosemary has major anti-inflammatory and antioxidant properties, helping to delay and inhibit tumour formation when consumed in therapeutic doses. This has been shown to be useful in skin, colon and breast cancers. It also has the ability to be used as an adjuvant to chemotherapy as it shows an ability to enhance the effectiveness of conventional chemotherapy treatment of breast cancer.
Antispasmodic & anticonvulsant
Rosemary oil has shown antispasmodic activity in both smooth muscle and cardiac muscle in animals, possibly due to its regulation of the neurotransmitters acetylcholine and histamine.
Multiple uses
Apart from the uses above, herbalists use rosemary to treat dizziness due to inner ear problems as well as nerve conditions, headaches, halitosis and stomach ailments, and for pain relief. It is also used in rheumatic liniments and ointments for its soothing anti-inflammatory effect.
Rosemary as a food
Rosemary is a strongly flavoured herb and its leaves are quite tough. Used sparingly, rosemary is a perfect match for roasted Mediterranean vegetables, lamb or any dish in which garlic, olive oil (and red wine) predominate. It is a major component of the traditional bouquet-garni used frequently in European cooking. It also works well in sweet and savoury biscuits.
The flowers, which have a delicate flavour, can also be eaten in salads or with cheese or meats.
Cautions
Hypersensitive individuals may experience reddening and dermatitis in rosemary oil applied topically, but the herb is generally perceived as safe with low toxicity. No drug interactions have been documented. It is not advised to be consumed in large amounts (greater than food levels) during pregnancy and lactation.
Overall, rosemary is an excellent and tasty plant that has been used widely in medicine and cosmetics as well as for the flavouring of foods. It is a powerful antioxidant, protects the liver and is antimicrobial, anti-inflammatory and a successful enhancer of memory and cognition.
In Australia, we know rosemary well. Sprigs are worn on ANZAC Day to signify remembrance and the herb grows wild on the Gallipoli Peninsula in Turkey.
- References available on request.
