Q: Of the nutrients in plant foods, it seems like flavonoids might be special regarding brain health. What do we know? A: Science already touts heart-health benefits of plant-based diets like the Mediterranean, MIND and DASH diets. Researchers are discovering how plant-based eating also may an important role in cognitive fitness and perhaps help prevent dementia, including Alzheimer’s disease. And one class of nutrients in plants continues to stand out: flavonoids. They have six subclasses: anthocyanidins, flavan-3-ols, flavanones, flavones, flavonols, and polymers. A variety of fruits and vegetables contain flavonoids. Some of the highest amounts are in berries, apples, citrus fruit (oranges, lemons), grapes, spinach, legumes, kale, broccoli, soybeans, onions, tea, cocoa, and wine. Some foods contain only one subclass of flavonoids, while others have several. Researchers believe flavonoids may help the brain in several ways. For instance, studies suggest they reduce cell-damaging free radicals and soothe inflammation. Some early-stage …