In this sport you can fairly control the extreme end.
Water is generally softer than icy snow, trees and rocks.
13 years of kiteing, started at 50, no major issues.
If you follow the recommendations on the safety thread above and refrain from doing kid's tricks, you might survive
Ahh.. and before you start, be sure that you get lessons with
thorough safety theory and practice.
Also use a seat harness [not waist] - less load on your back.
Notwithstanding the above, the sport is strongly recommended for ol' farts.
You can verify this by checking on the age statistics of forum members that participated in these polls:
viewtopic.php?f=81&t=2359454&start=60&hilit=old+poll
viewtopic.php?f=1&t=2389496&start=10&hilit=old+poll
The poll is not rock science, but you can appreciate that many elders practice kitesurfing.
Enjoy