What are some things i can do now to prevent arthritis later in life?

Arthritis prevention: There are different types of arthritis. If you are talking about osteoarthritis which is the most common form, much of this is genetically pre-determined. Having said that, given that it is largely a mechanical issue with cartilage erosion, how you use your joints has some bearing though far from complete. Other factors such as diet and supplements are still open for discussion.

Stay healthy: Stay healthy overall, don't smoke (may be related to some forms of arthritis), exercise moderately ("use it or lose it"), and try to maintain a healthy weight.