Preventing Arthritis

There's something about having a birthday that makes you think about how you're going to grow old. Even if the birthday is a 24th birthday. :P

So I was thinking: I take after my dad's side of the family, physically speaking. My grandmother has arthritis (the osteo kind, rheumatoid is for sissies). My dad's sisters all have osteoarthritis. AFAIK, it's been in the family for generations. It's a pretty safe bet I'm going to have it.

Point Number One: Arthritis sucks.

Point Number Two: The kind that's in my family really sucks, because my aunts have all been slowly losing mobility since they turned 50. By the time they're 75 they're going to need a wheelchair all the time.

Point Number Three: You can bet they're going to live to see 75, and more. Longevity also runs in the family, too - grandmother is 90-something. So cross "quick, merciful death" off my list of coping strategies.

My thinking is, people, I don't want to have this disease. The internet, however, is woefully inadequate when it comes to how to prevent arthritis. They have diets and exercise regiments and everything planned out for heart disease, and I was hoping something along those lines for arthritis, too, seeing as how it affects 80% of the population over 50... but nada. Nothing.

I did have some site tell me I shouldn't do exercises that put repeated, jerky pressure on my knees (like running), but I already knew that.

So anyone here know anything about the exercises to do and the foods to eat that'll gently encourage my cartilege and inter-jointal fluid to hang around till I'm definitely dead?