Dietary blueberry improves cognition among older adults in a randomized, double-blind, placebo-controlled trial
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As populations shift to include a larger proportion of older adults, the necessity of research targeting older populations is becoming increasingly apparent. Dietary interventions with blueberry have been associated with positive outcomes in cell and rodent models of aging. We hypothesized that dietary blueberry would improve mobility and cognition among older adults.
In this study, 13 men and 24 women, between the ages of 60 and 75 years, were recruited into a randomized, double-blind, placebo-controlled trial in which they consumed either freeze-dried blueberry (24 g/day, equivalent to 1 cup of fresh blueberries) or a blueberry placebo for 90 days. Participants completed a battery of balance, gait, and cognitive tests at baseline and again at 45 and 90 days of intervention.
Significant supplement group by study visit interactions were observed on tests of executive function. Participants in the blueberry group showed significantly fewer repetition errors in the California Verbal Learning test (p = 0.031, ηp2 = 0.126) and reduced switch cost on a task-switching test (p = 0.033, ηp2 = 0.09) across study visits, relative to controls. However, no improvement in gait or balance was observed.
These findings show that the addition of easily achievable quantities of blueberry to the diets of older adults can improve some aspects of cognition.
KeywordsAging Blueberry Cognition Gait Postural Sway
Attention network task
California verbal learning test, 2nd ed.
Diet history questionnaire II
Falls efficacy scale-international
Fall history questionnaire
Functional magnetic resonance imaging
Geriatric depression scale
Human Nutrition Research Center on Aging
Physical activity questionnaire
Profile of mood states
Computer/treadmill proficiency questionnaire
Virtual morris water maze
Compliance with ethical standards
This study was approved by the Tufts Medical Center Institutional Review Board and was performed in accordance with the ethical standards laid down in the 1964 Declaration of Helsinki and its later amendments. All study participants gave their informed consent prior to their participation in the study.
Conflict of interest
All authors read and approved the final manuscript. The authors declare that they have no conflict of interest.
U.S. Department of Agriculture, U.S. Highbush Blueberry Council, Tufts University.
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