Flavonoids, specifically quercetin, are antioxidants that help fight inflammation. They're found in fruits and vegetables, so make sure to have adequate amounts for your daily meals. For fruits, you can try apples, cherries, blueberries, grapes, and bananas. For vegetables, you can try broccoli, spinach, onions, and kale. Flavonoids are also found in grains, dark chocolates, red wine, and black and green teas.