Supporting cognition: Blueberries may promote neuronal activation to help ward off dementia

10 Jan 2019 --- Blueberry supplementation may benefit older adults at increased risk of dementia, according to new research. In a randomized, double-blind, placebo-controlled trial, researchers detected altered neuronal activation following blueberry supplementation in older adults with Mild Cognitive Impairment (MCI). The results suggest that anthocyanin-rich berries may hold promise in supporting cognitive functions.

The participants were aged 68 and over and randomized to take freeze-dried, whole fruit blueberry powder or a placebo powder every day for 16 weeks. The daily dose was the equivalent of one cup of whole blueberry fruit. Functional Magnetic Resonance Imaging (fMRI) was performed at baseline and the end of the study, while participants took a working memory challenge to determine any alterations in brain functions. 

After 16 weeks, participants in the blueberry group demonstrated significantly increased blood oxygen level-dependent (BOLD) signals in two areas of the brain during the working memory challenge. The changes in BOLD signals were of a large magnitude, suggesting that blueberry powder modulated neuronal signaling and improved neurovascular function.

The changes were not accompanied by significant improvements in working memory task performance. The authors propose that this might be due to the small sample size, as only a total of 17 participants completed the study. 

The blueberry powder, sponsored by the US Highbush Blueberry Council, was a mixture of 50 percent Vaccinium ashei Reade (Tifblue) and 50 percent V. corymbosum L (Rubel) blueberries.

This clinical trial was the first to detect altered neuronal activation after blueberry supplementation in older adults with MCI. Numerous studies support that anthocyanins are beneficial to health, however. 

Concord grape juice, high-flavanol cocoa supplementation and Montmorency cherries are all touted as holding health properties. Previous studies on Montmorency tart cherries have ranged from heart health and exercise recovery to sleep to potential gut health benefits.

Anthocyanins are red-pigmented flavonoids that give certain fruit and vegetables their rich red, purple and blue colors. They are found in berries, black soybean, black rice and cherries.

Additionally, anthocyanins may increase the function of the sirtuin 6 enzyme in cancer cells, according to a study from the University of Eastern Finland. The regulation of this enzyme could open up new avenues for cancer treatment. The findings were published in Scientific Reports.