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Fish oil & Omega-3

Consuming omega-3 fatty acids, a type of polyunsaturated fat, may help reduce symptoms in people suffering from rheumatoid arthritis because of their ability to modulate the inflammatory process.1 There are two main forms of omega 3 fatty acids: docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). These omega 3’s can be found in foods such as fatty fish, flaxseeds, chia seeds, and walnuts. Omega-3 fatty acids are also available in a supplement, typically in the form of fish oil.2

If you decide you would like to try a fish oil supplement, always consult with your doctor before you add the supplement. Consider working with a registered dietitian nutritionist, to determine which brands are safe and actually contain the listed ingredients. Fish oil can interact with certain medications such as blood thinners or medications used for high blood pressure. In addition, some fish oil supplements have been found to contain unhealthy levels of PCBs, which are dangerous toxins and known carcinogens.3 If you’re pregnant or breastfeeding, discuss with your physician a safe dose and brand.

Fish oil and RA

Among different dietary interventions used to treat RA, fish oil supplementation shows the most promise. One recent study found that patients who received 5.5 grams daily of fish oils in combination with triple disease-modifying anti-rheumatic drug (DMARD) treatment (methotrexate, sulphasalazine and hydroxychloroquine) were more likely to achieve remission. These findings suggest that medication and fish oil supplements may be a powerful combination in helping people with RA.4

Keep in mind that the overall quality of your diet can affect how well the fish oil supplements work. A diet low in omega-6 fatty acids can help maximize the anti-inflammatory effects of omega-3 fatty acids. Including olive oil in your diet may provide additional benefits when taking fish oil supplements.

How much do I need?

With so many fish oil supplements on the market, it can be difficult to determine which brands are safe and what dose you need. There is no officially recommended amount of fish oil supplementation for patients with RA. Most fish oil supplements provide a 3:2 or 2:1 ratio of EPA to DHA respectively. Individuals should speak to their physician prior to beginning supplementation.

Fish oil is available in both capsule and liquid form. If you choose to use liquid fish oil, read the label to carefully determine the amount to take.

Most studies of fish oil in people with RA have found that anti-inflammatory benefits are only achieved after at least 12 weeks of continuous use.1

Are there side effects?

Side effects of fish oil supplementation are generally mild, such as fishy-tasting burps, upset stomach, and mild diarrhea.1 If you are experiencing these side effects, try taking smaller doses throughout the day, and be sure to consume the pill with food to increase absorption.

Fish oil supplements may interfere with blood clotting and increase the risk for stroke, particularly if they are taken in combination with aspirin or other non-steroidal anti-inflammatory drugs (NSAIDs).1 Talk to your doctor about all your medications and supplements before starting on fish oil supplements.

Written by: Jonathan Simmons and Emily Downward | Last reviewed: September 2019.
  1. Koch C. Nutrition and rheumatoid arthritis. Johns Hopkins Arthritis Center. Available at Accessed 6/14/18.
  2. LeWine H. Fish oil: friend or foe? Harvard Medical School. Available at Accessed 6/15/18.
  3. Should you consider taking a fish oil supplement? Harvard Medical School. Available at Accessed 6/15/18.
  4. Proudman SM, James MJ, Spargo LD, et al. Fish oil in recent onset rheumatoid arthritis: a randomised, double-blind controlled trial within algorithm-based drug use. Ann Rheum Dis. 2015 Jan;74(1):89-95. doi: 10.1136/annrheumdis-2013-204145. Epub 2013 Sep 30.