Pomegranate Juice Augments Memory and fMRI Activity in Middle-Aged and Older Adults with Mild Memory Complaints

Susan Y Bookheimer,Jesse A Brown,Brian A Renner,Mike Jones,Teena Moody,Arne Ekstrom,Gary W Small,Zhaoping Li,Susanne M Henning

doi:10.1155/2013/946298

Abstract

Despite increasing emphasis on the potential of dietary antioxidants in preventing memory loss and on diet as a precursor of neurological health, rigorous studies investigating the cognitive effects of foods and their components are rare. Recent animal studies have reported memory and other cognitive benefits of polyphenols, found abundantly in pomegranate juice. We performed a preliminary, placebo-controlled randomized trial of pomegranate juice in older subjects with age-associated memory complaints using memory testing and functional brain activation (fMRI) as outcome measures. Thirty-two subjects (28 completers) were randomly assigned to drink 8 ounces of either pomegranate juice or a flavor-matched placebo drink for 4 weeks. Subjects received memory testing, fMRI scans during cognitive tasks, and blood draws for peripheral biomarkers before and after the intervention. Investigators and subjects were all blind to group membership. After 4 weeks, only the pomegranate group showed a significant improvement in the Buschke selective reminding test of verbal memory and a significant increase in plasma trolox-equivalent antioxidant capacity (TEAC) and urolithin A-glucuronide. Furthermore, compared to the placebo group, the pomegranate group had increased fMRI activity during verbal and visual memory tasks. While preliminary, these results suggest a role for pomegranate juice in augmenting memory function through task-related increases in functional brain activity.

Highlights

As people age, their risk for cognitive decline increases
An estimated 40% of people 65 years and older have age-associated memory impairment characterized by selfperception of memory loss and a standardized memory test score demonstrating lower objective memory performance compared with young adults [1,2,3]
The subjects did not carry a diagnosis of mild cognitive impairment (MCI) and were screened using the mini-mental state examination (MMSE)

Summary

Introduction

Their risk for cognitive decline increases. An estimated 40% of people 65 years and older have age-associated memory impairment characterized by selfperception of memory loss and a standardized memory test score demonstrating lower objective memory performance compared with young adults [1,2,3]. One investigation used fMRI to examine the effects of antioxidants (flavonoids) in young healthy controls and demonstrated increased fMRI activity to cognitive challenge with flavonoid administration [43]; no studies to date have examined fMRI effects of antioxidant therapy in older adults with or without memory complaints To address this knowledge gap, we explored potential neuroprotective effects derived from polyphenols in pomegranate juice in older volunteers with mild memory complaints in a placebo-controlled, randomized, and doubleblind trial and measured three aspects: (1) metabolites of pomegranate juice using blood biomarkers; (2) effects of pomegranate juice on memory performance; and (3) evidence of functional MRI changes during memory activation. Together these metrics provide preliminary evidence of bioavailability, clinical efficacy, and brain mechanisms of pomegranate juice in older adults with memory complaints

Methods

Results

Discussion