Book excerpt: More than 30 years ago, a young Harvard pathologist offered the medical community a theory for the cause of one of today's biggest killers-- heart disease. It is called the Homocysteine Theory and is the medical breakthrough that inspired Andrew Weil to label Dr. McCully as a visionary medical pioneer well ahead of his time. This discovery has the potential to save millions, yet ironically destroyed Dr. McCully's medical career. Homocysteine, a byproduct of metabolism, has been discovered to be a better risk indicator of heart disease than high cholesterol. A simple B6 vitamin and folic acid play a major role in controlling homocysteine levels. This proven theory will change the way the medical establishment views and treats heart disease. Today, the medical community is beginning to accept Dr. McCully's findings transforming his story from medical heresy to legitimate medicine. Updated and revised, complete with a new introduction by Walter Wilett, this eye opening book combines Dr. McCully's personal story and scientific philosophy with a fascinating exposition of his discovery and a special program to make use of this information to improve overall health.