Mikhail Tereshchenko/TASS via Getty ImagesWhen 81-year-old John Harrison was just 14 years old, he received a blood transfusion following a major chest surgery. Harrison, known in Australia as \"The Man With the Golden Arm,\" produces a rare and powerful antibody in his blood called RhD immunoglobulin, or anti-D. When a pregnant woman with an Rh-negative blood type carries a baby with Rh-positive blood, the woman's body mistakenly treats the baby's red blood cells like an outside threat. The transfusion Harrison received as a teen may have contributed to the unique composition of the blood his body now produces, Australian doctors have theorized. Learn more about blood, blood types and diet in \"Eat Right 4 Your Type (Revised and Updated): The Individualized Blood Type Diet® Solution\" by Dr. Peter J.