Elson M. Haas, M.D., is the medical director of the Preventive Medical Center of Marin, an integrated health care facility in San Rafael, California. He has been a practitioner of integrated and preventive medicine for more than twenty-five years. His books Staying Healthy with Nutrition, The Detox Diet, The Staying Healthy Shopper’s Guide, and A Cookbook for All Seasons are classics in the modern health care field. Dr. Haas’s educational web site is www.elsonhaas.com.