The original saying was " eat an apple before going to bed and you will keep the doctor from earning his bread, which evolved into the current format noted in your question. Apples are fraught with vitamins, antioxidants, phytonutrients and other chemicals which prevent diseases. There is a study indicating one of apple's nutrients quercetin prevents neuron degeneration in the brain. This in turn may have a protective effect against certain types of dementia such as Alzheimer's disease. Cancers, hypertension, cardiac disease and diabetes display are reduced incidence for people who have ingested apples over a long period of time. A study of nearly 10,000 individuals shows a reduction in strokes with long term apple ingestion. The list of benefits of eating "raw"apples is long. One of nature's greatest foods apples should be part of everyone's diet if they are not allergic to them. Thank you for allowing me to answer your question. Mark Davis, MD