The salvia family of herbs — sage — has long been revered for its ability to improve mood and mind. While salvia officinalis is the most common form of sage in the US, S. lavandulaefolia (Spanish or lavender sage) is more popular in Europe. It has smaller leaves, a stronger flavour than S. officinalis and contains less thujone, a naturally occurring chemical that may be toxic in high dosages.

In a recent study, psychologist Andrew B. Scholey, Ph.D., of Northumbria University, Newcastle upon Tyne, tested the properties of a standardized oil of S. lavandulaefolia on 24 healthy male and female students. Standard clinical tests were used to assess the subjects' memory and mood before the study and then after giving them capsules containing 25 microlitres or 50 microlitres of the essential oil of sage or placebos. The memory and mood tests were given one, two and one-half, four, and six hours after ingestion of the capsule, and each dose was separated by a one-week ‘washout' period to avoid any cumulative effect of the herb.

The students' memory improved significantly one hour after taking sage oil supplements, with a trend toward improvement at four hours. No significant improvements occurred following the placebos. The most dramatic improvements related to three aspects of mood: feeling alert, calm, and contented. In general, the higher dosage of sage oil was more effective, and some of the benefits to mood lasted several hours. The herb is known to inhibit acetylcholinesterase, an enzyme that breaks down a neurotransmitter — the same mechanism of some anti-Alzheimer's drugs. It also contains many polyphenolic antioxidants that protect against free radicals in the brain.

Scholey concluded that sage might reduce some symptoms of advanced dementia, including agitation and disturbed mood.

Reference: Tildesley NTJ, Kennedy DO, Perry EK, et al. Positive modulation of mood and cognitive performance following administration of acute doses of Salvia lavandulaefolia essential oil to healthy young volunteers. Physiology & Behavior, 2005;83:699-709.