This 107-year-old British doctor is friends with the queen, treated Saddam Hussein and is still working

At 107-years-old, Dr. William Frankland is the world's oldest practicing doctor. Renowned in medicine as the "Grandfather of Allergy" and once the doctor of Saddam Hussein, London-based Frankland continues to consult several patients around the world. But what's the secret behind his longevity? Find out on this episode of "Lifers"!