On this episode of Vital Signs, Dr. Sanjay Gupta examines case studies involving patients who have shown improvement or, in some cases, reversed life-threatening disease. From Caldwell Esselstyn’s use of a whole-food, plant-based diet to treat heart disease to the lifestyle changes Brit Geoff Whitington used to bounce back from adult-onset diabetes, this episode shows there is hope for patients who are fighting for their lives.