Effects of a polyphenol-rich grape and blueberry extract (Memophenol™) on cognitive function in older adults with mild cognitive impairment: A randomized, double-blind, placebo-controlled study

Abstract

BackgroundPolyphenols are naturally occurring organic compounds found in plants. Research suggests that their intake reduces the risk of cognitive decline and related dementias. Grapes and blueberries are polyphenol-rich foods that have attracted attention for their potential cognitive-enhancing effects.PurposeExamine the effects of supplementation with a standardized and patented polyphenol-rich grape and blueberry extract (Memophenol™) on cognitive function in older adults with mild cognitive impairment.Study designTwo-arm, 6 month, parallel-group, randomized, double-blind, placebo-controlled trial.MethodsOne hundred and forty-three volunteers aged 60 to 80 years with mild cognitive impairment were supplemented with either 150 mg of Memophenol™, twice daily or a placebo. Outcome measures included computer-based cognitive tasks, the Behavior Rating Inventory of Executive Function (BRIEF-A), the Cognitive Failures Questionnaire, and the CASP-19.ResultsCompared to the placebo, Memophenol™ supplementation was associated with greater improvements in the speed of information processing (p = 0.020), visuospatial learning (p = 0.012), and the BRIEF-A global score (p = 0.046). However, there were no other statistically significant between-group differences in the performance of other assessed cognitive tests or self-report questionnaires. Memophenol™ supplementation was well-tolerated with no reports of significant adverse reactions.ConclusionThe promising results from this trial suggest that 6-months of supplementation with Memophenol™ may improve aspects of cognitive function in adults with mild cognitive impairment. Further research will be important to expand on the current findings and identify the potential mechanisms of action associated with the intake of this polyphenol-rich extract.

Feasibility and Preliminary Efficacy of American Elderberry Juice for Improving Cognition and Inflammation in Patients with Mild Cognitive Impairment

“…Therefore, it is also possible that elderberry consumption leads to better cerebrovascular parietal function and consequently more cognitive task-related (i.e., visuospatial problem solving, which involves both parietal and frontal regions [38]) neural activation. Finally, unlike previous findings, we did not observe improvement across memory or other aspects of executive function [33]. Other studies have also found improvement in speed of processing as a result of grape/blueberry extract consumption [33,34].…”

“…Our second hypothesis that elderberry juice consumption would lead to greater cognitive improvement than a placebo-control was only partially supported, as we only observed a trend towards greater elderberry improvement in one domain-visuospatial cognitive flexibility. This is in partial agreement with a previous study that found that a blueberry extract improves visuospatial learning in patients with MCI [33]. We offer several potential explanations for the present results.…”

“…Finally, unlike previous findings, we did not observe improvement across memory or other aspects of executive function [33]. Other studies have also found improvement in speed of processing as a result of grape/blueberry extract consumption [33,34]. Although we did not measure speed of processing/reaction time per se in this study, it is notable that the only metric in our visuospatial problem solving task where we saw improvement was for the speed in which visuospatial cognitive flexibility tasks were completed.…”

“…As predicted, the 3x daily dosage of elderberry juice over 6 months and associated cognitive and blood-based inflammatory marker assessment were feasible in patients with MCI. Six-month attrition rates (18% for elderberry; 15% for placebo) were comparable to other randomized clinical trials examining blueberry extract interventions in cognitively impaired populations across similar 6-month timeframes but with fewer (2x) daily doses (blueberry attrition rate ranged from 12% [33] to 14% [34]; placebo attrition rate ranged from 14% [34] to 20%). Reasons for drop-out in the elderberry condition (minor gastrointestinal issue or co-morbid medical occurrence) are also comparable to previous drop-out reasons reported in prior blueberry extract studies in patients with MCI [34].…”

“…Thus far, few studies have examined the effects of anthocyanins in a cognitively impaired population. One randomized placebo-controlled trial in older adults with MCI found that relative to a placebo juice, a polyphenol-rich grape and blueberry extract intervention led to greater 6-month improvements in speed of processing, visuospatial learning, and self-reported executive function [33]. Similarly, another study in older adults with self-reported cognitive decline found that a wild blueberry juice improved speed of processing to a greater degree than a placebo-control at 6 months [34].…”