It's not the travel that is aging him. It's the fact that he's drinking his lunches (and probably breakfast and dinner as well). Although alcohol is a pickling agent which can be used to preserve certain substances, it doesn't work so well with the human body.
I just got out of rehab. I took early retirement because I was going to die being on the road; 300 days a year, working in three countries & three languages and traveling well over 1,000,000 air miles.
My advice to all: Have your breakdown while you are still working for "your" company and document everything that is said to you. You may end up owning your own private Idaho