We’ve all heard that eating chocolate temporarily improves our brain function. There are even studies done about it, determining that moderate and short-term intake of chocolate improves the brain blood flow and oxygen levels thanks to flavanols – plant-based substances in cocoa that have antioxidant and anti-inflammatory effects.
Of course, the problem with chocolate is that it brings as many negatives as it does positives. Enter blueberries.
A recent placebo-controlled and double-blind study determined that eating a cup of blueberries can also have a drastic positive effect on the cognitive performance of healthy adults in the age range between 40 and 65 years. The study was conducted by doctors Adrian R. Whyte, Sajida Rahman, and others, and it was published in the European Journal of Nutrition.
The study is called “Improved metabolic function and cognitive performance in middle-aged adults following a single dose of wild blueberry” and its findings support previous research in the 24-30 year age groups which reached similar conclusions. Other studies also share these findings for healthy children, teenagers, and young adults.
The purpose of the study was to find out if these effects can be observed in healthy older adults as well.
The goal of the study isn’t to find treatments of cognitive ailments but to determine how healthy adults can improve their cognitive potential in an easy manner. To do that, the study used a small dose of blueberries. As per the study’s description, they used:
“The wild blueberry beverage consisted of 25 g freeze-dried whole wild blueberry (WBB) powder (~1-cup fresh weight) […] The WBB powder was mixed with water, frozen lemonade concentrate, and unsweetened Kool-aid for color and flavoring. The placebo beverage was matched as closely as possible for energy and macronutrient content using the same ingredients minus the WBB powder.”
How well was the study conducted?
The study worked with 35 participants between 40 and 65 years (average of 50.9). 23 were female and 12 were male, all of them were in good health and didn’t have any diagnosable cognitive impairments.
Despite the relatively small sample size, the study was very well conducted. It was randomized, placebo-controlled, and double-blind. This means that the participants were given two doses of powder over a period of time – one was the study’s freeze-dried wild blueberry WBB powder and one was a simple placebo.
Additionally, the administration of the blueberry powder and the placebo were randomized. Neither the participants nor the researchers knew when and who was given the placebo and when – the blueberry powder. This ensured that there wouldn’t be any bias from either side.
Before and after the ingestion of both the placebo and the blueberry powder, the participants went through a series of psychological tests. The tests aimed to assess both the executive abilities and the memory of the participants. There was also an Auditory Verbal Learning Task which measured the learning, recall, and recognition abilities of the participants.
A cued Go/No-Go task assessed the participants’ reaction times and response inhibition while a Modified Attention Network Task examined their susceptibility to response interference, i.e. how easily distracted they were after eating the blueberry powder and after eating the placebo.
The results?
The wild blueberry powder was determined to have positive cognitive effects in all participants and in almost all cognitive tests. There were also no observed negative side-effects which could be viewed as a possible mistake in the study but that’s unlikely given the very small amount of blueberries (25 g) ingested.
As the researchers summarize the results:
“WBB cognitive performance was improved in comparison to placebo on delayed recognition memory and aspects of executive function. Importantly, these benefits were found on more demanding elements of the tasks where some form of additional cognitive effort was required.”
They also observed improvements in the and the sustained attention capabilities of all participants. The results are very promising as blueberries present a nearly drawback-free way of improving one’s cognitive abilities in/before cog