Gerson Therapy is based on the belief that disease is caused by the accumulation of unspecified toxins, and attempts to treat the disease by having patients consume a predominantly vegetarian diet including hourly glasses of organic juice and various dietary supplements. Animal proteins are excluded from the diet under the unproved premise that tumors develop as a result of pancreatic enzyme deficiency. In addition, patients receive enemas of coffee, castor oil and sometimes hydrogen peroxide or ozone.