Medically reviewed by Nancy Carteron, M.D., FACR
Written by Lana Burgess 
Updated on June 14, 2020

People traditionally take cod liver oil to improve their bone health, and some use it for osteoarthritis. But does it help?

Arthritis is a very prevalent condition and a leading cause of disability.

There are two common types. Both can cause joint pain, inflammation, stiffness, and other issues that limit mobility.

- Rheumatoid arthritis (RA) is an inflammatory joint disease caused by a problem with the immune system.

- Osteoarthritis (OA) is a degenerative condition that causes joint cartilage to wear away, leading to bone damage.

This article explores whether fish oil could help treat arthritis and professional guidance for using it.

It is worth noting from the outset that the American College of Rheumatology and the Arthritis Foundation do not recommend using fish oil for OA because there is not enough evidence that it is beneficial.

Does fish oil help arthritis?

Fish oil may help reduce inflammation in joints.
Cod liver oil and fish oil contain high levels of two omega-3 fatty acids:

- docosahexaenoic acid (DHA)
- eicosapentaenoic acid (EPA)

Research — such as the studies that we cite below — indicates that EPA and DHA can both reduce inflammation. The role of fatty acids in curbing inflammation suggests that they may help treat RA and OA.

Fish oil and RA

A 2012 review looked at earlier research into the benefits of fish oil for treating RA. In particular, it explored the role of EPA and DHA in reducing joint swelling and pain.

The review found evidence that EPA and DHA from marine sources provided consistent but modest help in improving the following aspects of RA:

- joint swelling and pain
- morning stiffness in the joints
- disease activity
- the use of pain medication

According to a 2016 study, people with active RA who took daily omega-3 supplements were able to reduce their use of pain relief medication. The authors note, however, that this finding may only be true for people in hot climates.