Short-term study on the effects of rosemary on cognitive function in an elderly population

J Med Food. 2012 Jan;15(1):10-7. doi: 10.1089/jmf.2011.0005. Epub 2011 Aug 30.

Abstract

Rosemary (Rosmarinus officinalis L.) has traditional reputations that justify investigation for a potential role in reducing widespread cognitive decline in the elderly. A randomized, placebo-controlled, double-blinded, repeated-measures crossover study was conducted to investigate possible acute effects of dried rosemary leaf powder on cognitive performance. Twenty-eight older adults (mean age, 75 years) were tested using the Cognitive Drug Research computerized assessment system 1, 2.5, 4, and 6 hours following a placebo and four different doses of rosemary. Doses were counterbalanced, and there was a 7-day washout between visits. There was a biphasic dose-dependent effect in measures of speed of memory: the lowest dose (750 mg) of rosemary had a statistically significant beneficial effect compared with placebo (P=.01), whereas the highest dose (6,000 mg) had a significant impairing effect (P<.01). There were significant deleterious effects on other measures of cognitive performance, although these were less consistent. Speed of memory is a potentially useful predictor of cognitive function during aging. The positive effect of the dose nearest normal culinary consumption points to the value of further work on effects of low doses over the longer term.

Publication types

  • Randomized Controlled Trial
  • Research Support, Non-U.S. Gov't

MeSH terms

  • Aged
  • Aged, 80 and over
  • Antioxidants / adverse effects
  • Antioxidants / pharmacology
  • Antioxidants / therapeutic use*
  • Cognition / drug effects*
  • Cognition Disorders / prevention & control*
  • Cross-Over Studies
  • Dietary Supplements
  • Dose-Response Relationship, Drug
  • Double-Blind Method
  • Female
  • Humans
  • Male
  • Memory / drug effects*
  • Phytotherapy*
  • Plant Leaves
  • Plant Preparations / adverse effects
  • Plant Preparations / pharmacology
  • Plant Preparations / therapeutic use*
  • Powders
  • Rosmarinus / chemistry*

Substances

  • Antioxidants
  • Plant Preparations
  • Powders