Does Bacopa monnieri improve memory performance in older persons? Results of a randomized, placebo-controlled, double-blind trial

Abstract

Objective: The objective of this study was to investigate the effectiveness of Bacopa monnieri Linn. for improvement of memory performance in healthy older persons.

Study design: This was a randomized, double-blind, placebo-controlled trial.

Setting and participants: The trial took place in Lismore, NSW, Australia between February and July 2005. Ninety-eight (98) healthy participants over 55 years of age were recruited from the general population.

Interventions: Participants were randomized to receive an extract of Bacopa monnieri called BacoMind(TM) (Natural Remedies Pvt. Ltd.), 300 mg/day, or an identical placebo. Following screening, neuropsychologic and subjective memory assessments were performed at baseline and at 12 weeks.

Outcome measures: Audioverbal and visual memory performance were measured by the Rey Auditory Verbal Learning Test (AVLT), the Rey-Osterrieth Complex Figure Test (CFT), and the Reitan Trail Making Test (TMT). Subjective memory performance was measured by the Memory Complaint Questionnaire (MAC-Q).

Results: One hundred and thirty-six (136) subjects volunteered; 103 met entry criteria, 98 commenced, and 81 completed the trial. Bacopa significantly improved verbal learning, memory acquisition, and delayed recall as measured by the AVLT: trial a4 (p = 0.000), trial a5 (p = 0.016); trial a6 (p = 0.000); trial a7 (delayed recall) (p = 0.001); total learning (p = 0.011); and retroactive interference (p = 0.048). CFT, MAC-Q, and TMT scores improved but group differences were not significant. Bacopa versus placebo caused gastrointestinal tract (GIT) side-effects.

Conclusions: Bacopa significantly improved memory acquisition and retention in healthy older Australians. This concurs with previous findings and traditional use. Bacopa caused GIT side-effects of increased stool frequency, abdominal cramps, and nausea.