A long-term berry study that tested the memory of female nurses who were over 70 years old found that those who had regularly eaten at least two servings of strawberries or blueberries each week had a moderate reduction in memory decline. (The effects of strawberries might be debatable, though, since that study was partly funded by the California Strawberry Commission and another study focusing on strawberries suggested that you’d need to eat roughly 10 pounds of strawberries per day to see any effect).