[inglor_cz]

Astronauts in the 1960s were required to be perfectly healthy before their mission, not even minor anomalies in bloodwork etc. were tolerated. No surprise that a third of the moonwalkers is still alive at approximately 90.

Nowadays the tolerance is somewhat bigger.

[kjkjadksj]

Not to mention when you understand so much about the bodies physiology, its probably hard to allow yourself to fall out of shape considering you know better than most what that means.

[keybored]

There are doctors who smoke… it is known. ;)

EDIT: And then an anecdote: a nurse student told me that almost all of her co-students consume tobacco. Hmm.

[keybored]

Fine point which has nothing to do with my comment.