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The importance of omega-3 fatty acids (omega-3 polyunsaturated fatty acids (PUFAs)) in fish oil has been a topic of research due to the building evidence of their protective effects on the brain, heart, eyes, and musculoskeletal system.
Types and Sources of Omega-3
There are three major omega-3 fatty acids:
- Eicosapentaenoic acid (EPA)
- Docosahexaenoic acid (DHA)
- Alpha-linolenic acid (ALA)
EPA and DHA are macronutrients not synthesized in the body but are concentrated in large amounts in the flesh of marine animals.
Plants are the major source of ALA, which can be converted to EPA and DHA in the liver but in limited quantities. Thus, it is more efficient to increase the intake of EPA and DHA through the diet or supplements, upon the recommendation of your doctor.
Plant sources of omega-3 fatty acids:
- Chia seeds
- Canola oil
Omega-3 supplements include:
- Fish oil
- Fish liver oil such as cod liver oil, which also contains vitamins A and D
- Krill oil
- Algal oil
- Flaxseed oil, a source of ALA
Note: The American Heart Association recommends eating 2 servings (1 serving = 4 oz cooked fish) of fatty fish per week. (1) Approximately 8 oz of fatty fish provides 1–4 g of EPA+DHA.
Fish Oil for Arthritis
Rheumatoid arthritis is a chronic autoimmune disease characterized by pain, swelling, and joint destruction. It is caused by the overproduction of certain PUFAs that are responsible for the natural inflammatory processes in the body. (2)(3)
A survey in the United States found that 90% of people diagnosed with arthritis have used alternative therapies for pain reduction, which include fish oil supplements. (4) It was found that patients who consumed fatty fish more than two times a week had lesser values of an inflammatory marker (C-reactive protein) than those who consumed fatty fish less than once a month. (5)
The benefits of fish oil are thought to be due to its high concentration of EPA and DHA, which help in reducing the inflammatory mediators (prostaglandin E2, leukotriene B4 cytokines, and reactive oxygen species) in the joint space.
This helps alleviate the pain associated with rheumatoid arthritis and allows a reduction in the use of analgesics (NSAIDs) and disease-modifying drugs (steroids, immunosuppressants). The beneficial effect, though, is not immediate and takes at least 3–4 months to set in. (6)
However, note that cod liver oil, in addition to being a good source of EPA and DHA, contains high amounts of fat-soluble vitamins A and D, which, when consumed at anti-inflammatory doses, may produce vitamin toxicities. (7) Therefore, it is imperative to consult your doctor about the use and dosage of fish oil supplements.
Dosage of Fish Oil
Various studies suggest a dose-response relationship between fish oil supplementation and its anti-inflammatory effects, with a threshold dose of 2.7 g/day of EPA. This daily intake of EPA plus DHA is roughly provided by 9 standard fish oil capsules. (8)
If a liquid fish oil preparation is your choice, then it is advised to layer the amount over 30 ml of juice (without stirring) and take it in a single gulp. This should be followed by slowly sipping 30 ml of juice to remove any unpleasant taste from the lips.
Fish Oil-Associated Vitamin E Deficiency
An increased intake of PUFAs can decrease vitamin E levels in the body. However, multiple factors are at play, including the degree of unsaturation of the PUFAs.
This means that the higher the unsaturated PUFAs, the higher the vitamin E requirement. The baseline level of vitamin E for an increased intake of PUFAs is not yet established. (9)
Side Effects of Fish Oil
Taking fish oil supplements may cause:
- Bad taste
- Bad breath
- Loose stools
Because fish oil is highly unstable, it is subject to oxidation and rancidity, which may cause the common gastrointestinal side effects. (10)
To avoid these side effects:
- Avoid aerated drinks before consuming fish oil supplements.
- Take supplements before meals.
- Avoid consuming liquids immediately after taking fish oil.
- Refrigerate liquid fish oil.
Consult your healthcare provider if you are taking medication that affects blood clotting or if you are allergic to fish.
Drug and Fish Oil Interactions
Fish oil and conventional medication have several beneficial interactions to treat rheumatoid arthritis:
- Fish oil and NSAIDs: Fish oil and NSAIDs work by inhibiting cyclooxygenase, which is the main enzyme involved in generating inflammatory mediators. One study found that fish oil supplementation reduced conventional analgesic use and gastric irritancy in patients with rheumatoid arthritis. (11)
- Fish oil and cyclosporine: Cyclosporine is an immunosuppressant commonly used in moderate to severe forms of rheumatoid arthritis. Its side effects include hypertension and kidney toxicity. Fish oil, through its effect on reducing proinflammatory mediators, decreases these side effects of cyclosporine. (12)
However, omega-3 supplements may interfere with the action of certain drugs as well. It reacts with blood-clotting medications and can increase the risk of bleeding.
Fish oil supplementation can be considered for arthritis, along with first-line drugs such as analgesics (ibuprofen, diclofenac), due to its anti-inflammatory effects.
Fish oil can be found in abundance in cold-water fish or may be taken as supplements. However, its use must be approved by your doctor as it can cause gastrointestinal disturbances, bad taste and smell, and headache. Higher doses may lead to bleeding tendencies in older adults.