Researchers from Harvard University looked at nearly 50,000 women around 48 years old and more than 27,000 men around 51 years old at the start of the study. Over the course of 20 years, participants answered survey questions about their food intake. The data was used to determine how many and what type of flavonoids the participants were consuming on a daily basis.
The participants were also asked to evaluate their cognitive abilities twice during the study to see how their memory and brain function changed over time. At the end of the trial, researchers found people who ate half a serving of flavonoid-rich foods per day had a 20% lower risk of cognitive decline.
Of the flavonoids eaten, flavones (found in yellow and orange fruits and veggies) and anthocyanin (found in blueberries, blackberries and cherries) had the most protective properties, lowering cognitive decline by 38% and 24% respectively.