> The study excluded anyone who said they consumed more than five portions of fruit and vegetables per day, and all participants were told to stick to their normal diet throughout.
So the effect is probably related to any vegetable, not something special about blueberries.
> Before and after the 12-week period, participants took a range of cognitive tests while an MRI scanner monitored their brain function and resting brain blood flow was measured. Compared to the placebo group, those who took the blueberry supplement showed significant increases in brain activity in brain areas related to the tests.
The redaction is very suspicious. They don't claim that they improved in the test, they get some kind of indirect evidence that perhaps is not useful at all.
From the abstract of the article:
> There was also evidence suggesting improvement in working memory (two back test) after blueberry versus placebo supplementation (p=0.05).
This smell as p hacking, i.e. they did a lot of test, most of them were not conclusive, but by chance one of the many variations they test had p=0.05.
