Thursday on "The Alan Colmes Show," Alan spoke with Dr. Aubrey de Grey, a world renowned expert on aging who discussed why getting older should be considered "the world's most important problem," and how people could one day live to 1000 years old.

Dr. de Grey told Alan that the secret to a long life could be tests done on middle aged mice, why no one should ever talk about immortality, and how he responds to critics about his methods of research.