Is it okay to eat fish supplements efen if you don't have arthritis?

Eat fish not pills. It is better to eat wild fish like salmon from alaska then to take fish oil supplements. While fish oil naturally has anti-inflammatory and anti-coagulant properties, you can eat it safely even if you don't have a known problem. 3 to 4 times a week is safe. Don't bother with pills.
Yes. Fish oil supplements have been found to reduce the risk of heart disease, as well as certain cancers, and possibly even improve healing of injuries and improving mentation.