Book excerpt: Phytochemicals as Bioactive Agents focuses on the mechanisms of action of phytochemicals identified as displaying bioactivity in the prevention of cancer, heart disease and other diseases and the prospects for developing functional foods containing these bioactive compounds. Internationally recognized experts present the latest research findings on the antimutagenic and anticarcinogenic effects of tea and tea constituents; chemoprevention provided by plants in the family Cruciferae and genus Allium; anticarcinogenic effects of carotenoids and curcumins; the chemistry and application of alfalfa saponins; the bioactive components of rice bran and rice oil; the effects of garlic on lowering serum cholesterol; and using phytochemicals to optimize gastrointestinal tract health and function.