Tom Cruise Good Genes or Good Docs?

12/18/2011 3:30 AM PST

Tom Cruise: Good Genes or Good Docs?

Tom Cruise's mission impossible is aging.

Here's the handsome 30-year-old "Far and Away" star back in 1992 (left) -- and 19 years later, the flawless 49-year-old promoting his new movie "Mission: Impossible -- Ghost Protocol" in London this week (right).

What's his secret?