Are There Health Benefits to Taking Fish Oil?

Medically Reviewed by Christine Mikstas, RD, LD on November 14, 2022
3 min read

Fish oil is derived primarily from anchovy, herring, and pilchard. The process involves pressing cooked fish, then using a centrifuge to separate the oil from the extracted fluid.

Fish oil has many uses. It’s found in industrial compounds, paint, soap, and cosmetics. Leather, rubber, and wax production also rely on fish oil as part of processing. For decades, it has been added to some margarine and cooking oils to boost their nutritional value.

Fish oil is an essential source of omega-3 fatty acids in addition to vitamin A and vitamin D. Half a century ago, Danish scientists noticed specific Inuit populations had lower rates of heart disease. Researchers concluded that the comparative rarity of heart disease was due to diets rich in fatty fish like salmon, herring, and sardines.

Since that discovery, further studies have investigated whether omega-3 fatty acids are anti-inflammatory, decrease blood clot formation, and reduce heart rhythm problems.

Two capsules of a fish oil supplement contain: 

  • Calories: 25
  • Protein: 0 grams
  • Fat: 2 grams
  • Carbohydrates: 0 grams
  • Fiber: 0 grams
  • Sugar: 0 grams

Fish oil capsules are a good source of: 

Fish oil is an excellent source of omega-3 fatty acids. Omega-3 fatty acids are essential for the proper development of the eyes, brain, and reproductive cells. They are also vital for heart and lung health, in addition to optimal functioning of the immune and endocrine systems.

Research has found that regular fish consumption reduces the risk of death from all causes. Several potential health benefits of fish oil supplements are:

Prevention of Heart Disease and Heart Attacks

Multiple studies have confirmed that eating fish can help prevent coronary heart disease. The more fish in your diet, the lower the risk of death from heart disease and stroke. One study found that subjects treated with fish oil supplements after experiencing a heart attack had a 29% reduction in fatal cardiac arrhythmias.

Improved Cognitive Function

The DHA found in fish oil supplements has been proven to protect against Alzheimer’s disease and dementia. Researchers have also concluded that increased DHA consumption reduces the risks of diseases that often accompany Alzheimer’s, like diabetes and cardiovascular disease. 

Alleviation of Rheumatoid Arthritis

Epidemiological studies suggest that omega-3 fatty acids prevent rheumatoid arthritis. One study found that these fatty acids control joint swelling, and it’s believed that they also help to alleviate autoimmune inflammation, the cause of rheumatoid arthritis. 

You should always consult with your doctor before taking any new supplements. Consider the following before taking fish oil:

Medication Interference

Avoid fish oil if you are taking anticoagulant medication. Fish oil decreases blood clot formation, increasing the risk of bleeding for those on Warfarin or low-dose aspirin.

Cancer and disabilities at birth

Be sure to research brands of fish oil, as not all are created equal. Certain brands are certified free from polychlorinated biphenyls (PCBs), which are believed to cause cancer and disabilities at birth. Make sure the supplement you choose is also tested for toxic metals like mercury.

Show Sources


American Journal of Clinical Nutrition: “Historical overview of n-3 fatty acids and coronary heart disease.”

Britannica: “Fish Oil.”

Circulation: “Fish Consumption, Fish Oil, Omega-3 Fatty Acids, and Cardiovascular Disease.”

ESHA Research, Inc., Salem, Oregon: “Fish Oil.”

Harvard Heart Letter: “Should you consider taking a fish oil supplement?”


Lipid Technology: “Fish oil: production and use now and in the future.”

Mayo Clinic: “Fish oil.”

Mediterranean Journal of Rheumatology: “The Effect of Omega-3 Fatty Acids on Rheumatoid Arthritis.”

National Institutes of Health: “Omega-3 Fatty Acids.”

Pediatrics: “Fish, Shellfish, and Children’s Health: An Assessment of Benefits, Risks, and Sustainability.”

Prostaglandins, Leukotrienes, and Essential Fatty Acids: “Omega-3 fatty acids and dementia.”

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