RESEACH TITLE: Effects of dietary blueberry on cognition and in vivo and in vitro inflammatory status
COUNTRIES: United States
CONDUCTED BY: Neuroscience and Aging USDA-ARS, HNRCA at Tufts University Boston MA United States
PUBLISHED ON: The FASEB Journal
Chronic inflammation is thought to play a role in age-related cognitive decline. Previous studies from our laboratory have shown that dietary intervention with darkly pigmented berry fruit can reduce systemic and central biomarkers of inflammation while reversing behavioral impairments in aged rats. In the present study, older men and women (60-75 years old) were recruited for a randomized, double-blind, placebo-controlled trial, in which they consumed freeze-dried blueberry (BB) powder or a seemingly identical placebo for 90 days. Blood samples were collected on intervention days 0, 45, and 90 when participants visited the center to complete a battery of cognitive tests. Participants that consumed the blueberry powder significantly (p < 0.05) reduced the number of errors made on a task switching test over the course of the intervention. Based on this test, participants with high or low error rates were selected from each intervention group, and their fasted serum was used to treat HAPI rat microglial cells, in vitro, for 8 hours prior to an overnight lipopolysaccharide (LPS) challenge. While no difference in TNF-α was observed between the sera from the two groups, cells that were treated with serum from participants that consumed BB showed decreased levels of LPS-induced inflammatory stress-mediated signals, e.g., TNF-α, relative to placebo (p< 0.05). In vitro inflammatory response in the HAPI cells reflected cognitive performance among participants. These findings suggest that dietary intervention with blueberry may be able to delay or reverse age-related cognitive decline by reducing neuroinflammation.