Blueberries may enhance executive function in youth

A study published in Food & Function suggests that consuming a flavonoid-rich wild blueberry beverage may enhance executive function in children aged 7–10. The study, led by Claire Williams and Adrian Whyte from the School of Psychology & Clinical Language Sciences at the University of Reading in England, is the first to examine the effects of a flavonoid intervention on an executive function task where the researchers increase or decrease the cognitive demand—making the task easier or more difficult to perform across different trials. Executive function is a set of mental skills, controlled by frontal lobe area of the brain, that help us manage time, pay attention, and get things done.

“We have known for some time that flavonoids promote healthy brain function in adults and have also found that acute flavonoid intervention via a wild blueberry beverage has a positive effect on episodic memory in children,” said Williams.

In this double-blind cross-over study, 21 children aged 7–10 were tested with an executive function task after drinking a beverage containing 30 g of flavonoid-rich wild blueberry powder (equal to about 1¾ cup of frozen wild blueberries) or a matched placebo beverage. Participants were tested on three occasions over a two-week period (a baseline session followed by two test sessions). There was a seven-day wash-out between each treatment. For the 24 hours before each test session, participants were asked to consume a low flavonoid diet. On each test day, the participants consumed a low flavonoid lunch consisting of a ham or cheese sandwich, bag of plain chips, and a banana, provided by the parent/legal guardian.

The researchers found that the children could perform the tasks significantly faster after consuming the wild blueberry beverage. This effect was most evident on incongruent and high load trials, suggesting performance can be maintained on the more cognitively demanding aspects of the task following wild blueberry treatment when compared with placebo. Conversely, a cueing effect was found where wild blueberry treatment positively affected phasic alertness, indicating that a higher level of cognitive demand may not always be necessary for a difference to be shown.

Study