Without nutritious whole foods, the four-step defense process can not function properly. While our bodies require nutrition from a wide variety of food groups, studies have shown that plant foods - fruits, vegetables, and herbs - nourish the body in ways that other foods can not. The healing power of plant foods comes from vital nutrients called phytochemicals. Phytochemicals, such as antioxidants and polysaccharides, offer enormous promise in the fight to maintain optimal health.