Oil from fatty fish, including salmon, trout and sardines is a healthy diet choice. They are rich in Omega-3 oils that contain large amounts of essential fatty acids. These fatty acids are beneficial in treating and preventing several diseases, including asthma, Crohn's disease and gallstones. They are also beneficial if you suffer from arthritis.

The New Being Nutrition Blog says:

Omega-3 fish oil is an arthritis natural remedy because of the anti-inflammatory properties in the essential fatty acids which help to reduce the pain and swelling associated with osteoarthritis.

The Fish Oil Blog and Omega-3 News talks about using fish oil as a dietary supplement:

Fish oil is by far a more natural way of treating the cause, not just the symptoms. Just ensure that the fish oil is a 5 star pharmaceutical grade fish oil tested for its purity and potency by IFOS standards: