Book excerpt: Nutraceuticals are bioactive phytochemicals that protect or promote health and occur at the intersection of food and pharmaceutical industries. This book will cover a wider spectrum of human health and diseases including the role of phytonutrients in the prevention and treatment. The Book includes chapters dealing with biological and clinical effect, molecular level approach, quality assurance, bioavailability and metabolism of a number phytochemicals and their role to combat different diseases.