Berry polyphenols are associated with enhanced cognition and reduced inflammation in healthy, older adults

Authors: Shukitt-Hale, Barbara; MILLER, MARSHALL - Duke University; Fisher, Derek; BIELINSKI, DONNA - Jean Mayer Human Nutrition Research Center On Aging At Tufts University; SCOTT, TAMMY - Jean Mayer Human Nutrition Research Center On Aging At Tufts University

Submitted to: American Chemical Society Abstracts
Publication Type: Abstract Only
Publication Acceptance Date: 5/17/2018
Publication Date: 8/19/2018
Citation: Shukitt Hale, B., Miller, M.G., Fisher, D.R., Bielinski, D.F., Scott, T.M. 2018. Berry polyphenols are associated with enhanced cognition and reduced inflammation in healthy, older adults [abstract]. 256th American Chemical Society National Meeting & Exposition Program #AGFD 21.

Interpretive Summary:

Technical Abstract: The long-term effects of oxidative stress and inflammatory insults are thought to contribute to the decrements in cognitive performance seen in aging and neurodegenerative diseases; these changes include deficits in processing speed, executive function, memory, and spatial learning. Dark-colored berry fruit, such as strawberries and blueberries, which are high in polyphenols with antioxidant and anti-inflammatory properties, can prevent and even reverse age-related neuronal deficits in animal models of aging. In recent randomized, double-blind, placebo-controlled clinical trials conducted by our laboratory, healthy older adults (ages 60-75) consumed 24g of freeze-dried berry fruit (equivalent to 1 cup blueberries or 2 cups strawberries) per day, or a placebo powder for 90 days. Participants completed a battery of cognitive tests at baseline, 45 and 90 days following intervention. As observed in the animal research, berry fruit supplementation was able to improve some aspects of cognitive performance among older adults. Specifically, participants in the blueberry group showed enhanced executive function as evidenced by significantly fewer repetition errors in the California Verbal Learning Test (CVLT-II; p = 0.031) and reduced switch cost on a task switching test (p = 0.033) across study visits, relative to controls. Participants in the strawberry group showed enhanced learning and memory as evidenced by significantly improved probe trial performance in a virtual water maze during the midpoint visit (p = 0.020) and improved word recognition in the CVLT (p = 0.014). There was a relationship between cognitive performance and inflammation, as serum collected from blueberry- or strawberry-supplemented older adults reduced LPS-induced inflammatory-stress-mediated signals (e.g., nitric oxide, p < 0.05) in stressed HAPI microglia in vitro, relative to serum from placebo controls. Therefore, dietary interventions with polyphenol-rich berry fruit may be one strategy to forestall or even reverse age-related neuronal deficits, via decreases in inflammation, to help preserve cognitive function.