Spearmint Extract Improves Working Memory in Men and Women with Age-Associated Memory Impairment

Abstract

Objective: The purpose of this study was to investigate the effects of supplementation with a spearmint ( Mentha spicata L.) extract, high in polyphenols including rosmarinic acid, on cognitive performance, sleep, and mood in individuals with age-associated memory impairment (AAMI).

Design: Subjects with AAMI ( N = 90; 67% female; age = 59.4 ± 0.6 years) were randomly assigned ( n = 30/group) to consume 900, 600, or 0 mg/day (two capsules, once daily) spearmint extract for 90 days, in this double-blind, placebo-controlled trial. Assessments were completed for cognition (days 0, 45, and 90), sleep (days 0 and 90), and mood (days 0 and 90) by using the Cognitive Drug Research (CDR) System ^™, Leeds Sleep Evaluation Questionnaire (LSEQ), and Profile of Mood States (POMS ^™), respectively.

Results: Quality of working memory and spatial working memory accuracy improved after supplementation with 900 mg/day spearmint extract by 15% ( p = 0.0469) and 9% ( p = 0.0456), respectively, versus placebo. Subjects consuming 900 mg/day spearmint extract reported improvement in their ability to fall asleep, relative to subjects consuming placebo ( p = 0.0046). Overall treatment effects were evident for vigor-activity ( p = 0.0399), total mood disturbance ( p = 0.0374), and alertness and behavior following wakefulness ( p = 0.0415), with trends observed for improvements after spearmint supplementation relative to placebo.

Conclusions: These results suggest that the distinct spearmint extract may be a beneficial nutritional intervention for cognitive health in older subjects with AAMI.