Effects of blueberry supplementation on measures of functional mobility in older adults

Abstract

Limited functional mobility in older adults has been associated with declines in tests of motor, psychomotor, and executive function. Animal studies have demonstrated reversals in indices of motor and psychomotor function via supplementation with polyphenolic-rich foods such as blueberries. The purpose of this study was to examine whether 6 weeks of daily consumption of 2 cups of frozen blueberries affects functional mobility in older adults. Pre- and post-intervention assessments of grip strength, simple reaction time, adaptive gait, and executive function were completed for older adults (age >60 years) partially randomly assigned to a blueberry (BB) supplementation or a carrot juice drink control (CAR) group. Paired t tests were used to assess within-group effects for outcome variables in each supplementation group, and a mixed-model analysis of covariance (ANCOVA) was used to determine group (CAR vs. BB) differences. Mixed-model analysis indicated that the BB group demonstrated significant improvements relative to the CAR group in performance (i.e., number of step errors) of a challenging dual-task adaptive gait test that were independent of differences in gait speed. Within only the BB group, significant improvements were also seen in 3 other measures (i.e., usual gait speed; number of step errors during single-task adaptive gait; and gait speed during dual-task adaptive gait). These preliminary findings support the hypothesis that blueberry supplementation may provide an effective countermeasure to age-related declines in functional mobility and serve as justification for an expansion to larger trials to more fully assess this nonpharmacologic approach to maintaining optimal mobility and independence.