Plant foods contain thousands of natural chemicals called phytonutrients. These chemicals help protect plants from germs, fungi, bugs, and other threats. When humans consume phytonutrients, they may help prevent disease and keep the body functioning properly. Examples of phytonutrients include carotenoids, flavonoids, and glucosinolates. Carotenoids, found in yellow, orange, and red fruits and vegetables, act as antioxidants and support eye and immune health. Flavonoids, found in a variety of plant foods like green tea and citrus fruits, have antioxidant and anti-inflammatory properties. Glucosinolates, found in cruciferous vegetables like broccoli and kale, may help prevent cancer. Although phytonutrients are not essential for survival, incorporating them into your diet can provide various health benefits.