This is how their grandfathers and on back lived, they lived off the land and traded for what they need. The problem with that lifestyle is lack of modern day medical care and diverse eating habits. This might be why he looked a lot older than he was (assuming he wasn't doing any drugs or hard drinking). I know he died due to a boating accident but take a look at that aluminum boat they drove around in, it had all kinds of issues from what I could see.