Spearmint extract improves working memory in men and women with age-associated memory impairment

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=59.40.6 years) were randomly assigned (n=30/group) to consume 900, 600, or 0mg/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 900mg/day spearmint extract by 15% (p=0.0469) and 9% (p=0.0456), respectively, versus placebo. Subjects consuming 900mg/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.