To defend themselves from solar radiation and hungry herbivores, plants have created an arsenal of protective chemicals called polyphenols. Flavonoids are among the toughest of these, and they also fall into the antioxidant category. Flavonoid-rich fruits include apples, blueberries, cranberries, and grapefruit. Vegetables that boast flavonoids include asparagus, Brussels sprouts, cabbage, garlic, kale, kohlrabi, kidney and lima beans, onions, peas, and spinach. One study found that people who drank fruit and vegetable juices such as orange, apple, or tomato three times a week were less likely to develop Alzheimer’s disease. An animal study showed that pomegranate juice halved the risk of Alzheimer’s disease in rats. Other studies show that the more flavonoids a person eats, the lower the likelihood of developing dementia.