About Madeleine Marentette Madeleine Marentette operates Grail Springs, a luxurious wellness centre in Bancroft, Ontario, where she shares her secrets to living a healthy, vibrant, and brilliant life with hundreds of guests every year through diet, exercise, and reflection. Books by Madeleine Marentette Grail Springs Holistic Detox For Body, Mind & Spirit by (author) Madeleine Marentette foreword by Elson Haas