Data published in the European Journal of Nutrition indicated that 200 ml of the blueberry drink led to quicker reaction times, enhanced verbal memory performance, and better recall in 7-10 year olds, versus placebo.
On the other hand, no benefits on reading performance were reported by the scientists from the University of Reading and the University of London.
“Such findings add to the growing body of evidence that flavonoids are beneficial for healthy brain function, and in this instance demonstrate the potential benefits of a 30 g freeze-dried [wild blueberry] treatment, equivalent to a 240 g punnet or 1.5 cups of fresh blueberries when relating findings to real-world applications, during critical developmental periods,” they wrote.
Blueberries & memory
Studies in older adults have also found potential cognitive benefits of flavonoid-rich blueberry consumption. For example, a 2017 paper published in Applied Physiology, Nutrition, and Metabolism reported that 30 ml of blueberry concentrate per day (providing 387 mg anthocyanidins) for 12 weeks was associated with “significant increases in brain activity […] in response to blueberry supplementation relative to the placebo”. The researchers also report improved working memory in their subjects (adults approximately 68 years of age).
In addition, a 2010 study led by Robert Krikorian from the University of Cincinnati Academic Health Center found that a daily drink of about 500 mL of blueberry juice was associated with improved learning and word list recall, as well as a suggestion of reduced depressive symptoms in older people with early memory problems (Journal of Agricultural and Food Chemistry, Vol. 58, No. 7, pp 3996–4000).
The new study looked at children and acute consumption (ie. one dose). Fifty-four health children aged between 7 and 10 years old were randomly assigned to consume 200 ml of the blueberry drink (providing 253 mg anthocyanins) or placebo. Cognitive tests were performed two to six hours after consumption.
Results from the randomized, single-blind, parallel-groups study indicated that reaction times improved in the children consuming the blueberry drink, without any detrimental effects on accuracy.
In addition, blueberry consumption was associated with enhanced verbal memory performance, compared to placebo, but no effects were observed for reading.
“Chronic supplementation and other more sensitive reading measures should be considered for examining the effects of [wild blueberry] on such a complex skill in the future,” wrote the researchers.
Commenting on the potential mechanism of action, the UK-based researchers proposed that blueberry consumption may improve blood flow in the brain, but noted that “definitive mechanisms are currently unknown, especially in a child population”.
Source: European Journal of Nutrition
October 2019, Volume 58, Issue 7, pp 2911–2920, doi: 10.1007/s00394-018-1843-6
“The effects of acute wild blueberry supplementation on the cognition of 7–10-year-old schoolchildren”
Authors: K.L. Barfoot et al.