Effects of berry supplementation on mobility and cognition among older adults

Authors: Miller, Marshall; Shukitt-Hale, Barbara

Submitted to: Berry Health Benefits Symposium
Publication Type: Abstract Only
Publication Acceptance Date: 7/7/2015
Publication Date: 10/13/2015
Citation: Miller, M.G., Shukitt Hale, B. 2015. Effects of berry supplementation on mobility and cognition among older adults. Berry Health Benefits Symposium, 2015 Berry Health Benefits Symposium Pre-Proceedings; October 13-15, 2015,Madison, Wisconsin, p. 24-25.

Interpretive Summary:

Technical Abstract: Americans are now living longer than ever before; as a result, the number of people over the age of 65 is expected to double by 2050. During this same period, the number of people living with dementia is expected to almost triple. Even in the absence of specific neuropathology such as Alzheimer’s or Parkinson’s disease, age-related neurodegeneration leads to measurable declines in cognitive and motor function. Despite more likely causes of death, dementia is a chief health concern among older adults due to the loss of dignity, identity, and independence. While its causes are not yet entirely understood, neuroinflammation and oxidative stress are thought to underlie many of the processes and pathologies that lead to dementia. Epidemiological studies have found that diets rich in berry fruit, such as blueberries and strawberries, are associated with lower rates of age-related cognitive decline. Berry fruit contain a variety of neuroavailable phytochemicals, which can alter neuronal morphology and signaling as well as reduce neuroinflammation and oxidative stress. When aged rats consumed diets containing 2% blueberry or strawberry for 2 months, improvements in spatial working memory, balance, and coordination were observed relative to controls. Therefore, dietary interventions with berry fruit may represent a promising approach to slowing or preventing age-related neurodegeneration. Recently our lab has sought to translate the beneficial effects of berry fruit interventions from rodent models to older human populations. An initial study established methods for assessing age-related functional decline among older adults using tests that parallel those used in rodent models of aging. Seventy six healthy adults, between the ages of 21 and 75, completed a 1 hour mobility and cognition assessment. Increases in postural sway during quiet standing, decreases in gait speed, and impairments in spatial learning and memory were observed with age. To determine whether dietary intervention with blueberry could reverse age-related motor and cognitive decline among older adults, 38 healthy men and women between the ages of 60 and 75 years were recruited into a randomized, double-blind, placebo-controlled trial where they consumed 24g/d of freeze-dried blueberry powder (~1 cup/d whole blueberry) or a blueberry placebo powder for 90 days. Participants were tested at baseline and again at 45 and 90 days. Although no improvements in mobility were observed, participants that consumed blueberry made fewer repetition errors in a verbal learning task and fewer errors in a test of mental flexibility over the course of the study, relative to those in the placebo group. We are currently conducting a similar study involving 39 older men and women to determine whether dietary intervention with 24g/d strawberry (~2 cups/d whole strawberry) for 90 days can improve age-related changes in motor function and cognition. These findings provide evidence that supplementing older adults’ diets with berry fruits can improve cognition even during otherwise healthy aging.