10 Science-Backed Benefits of Cod Liver Oil

1. Heart health

Studies have shown that omega-3 fatty acids can help lower the risk of heart disease by reducing risk factors such as high cholesterol, hypertriglyceridemia, hypertension, and high homocysteine levels in the blood

The American Heart Association (AHA) recommends consuming 1-2 servings of fatty fish or fish oils per week to reduce the risk of congestive heart failure, coronary heart disease, ischemic stroke, and sudden cardiac death.

2. Immune health

Cod liver is rich in antioxidants in addition to vitamins A and D, which can boost immune cell function and strengthen your immune system. Evidence suggests that there is a positive association between fish oil supplements (including cod liver oil) and faster recovery from COVID-19 and improved health in those with long COVID syndrome. 

3. Brain health 

Regular consumption of omega-3 fatty acids has been found to reduce the risk of dementia, cognitive deterioration, and Alzheimer’s disease. This is because these fatty acids form the cellular membrane in the brain cells and maintain cell membrane integrity.

4. Pregnancy health

Consuming cod liver oil during pregnancy and breastfeeding is associated with fewer instances of premature birth, healthier infant birth weights, and better visual and cognitive development. 

A meta-analysis of 10 prospective cohort studies along with 5 randomized clinical trials on administering omega-3 to mothers during pregnancy and outcomes of children with eczema, rhino-conjunctivitis, and asthma suggest a protective association between higher maternal intakes of cod liver oil and healthier offspring.

However, pregnant women should always consult their gynecologists before starting fish oil supplements. Excessive amounts of vitamin A in the body during pregnancy can do more harm than good.

5. Cancer prevention

Because cod liver oil is rich in antioxidants, many experts believe that a higher intake of omega-3s from food or supplements may reduce the risk of various cancers in the elderly, especially gastrointestinal and breast cancer. Results from observational studies, however, have been inconsistent and vary according to other factors, such as gender and genetic predisposition.

6. Eye health

Fish oil supplementation has been shown to slow down age-related macular degeneration (AMD), especially in those with diabetes and hypertension. Advanced AMD is a major cause of severe vision loss, and many researchers suggest that the omega-3s in cod liver oil have protective effects on the retinal cells, which can boost eye health in the long run.

Cod liver oil can also ease symptoms of dry eyes. Omega 3 fatty acids (particularly eicosapentaenoic and docosahexaenoic acid) may help regenerate the mucus membrane in the conjunctiva and reduce grittiness in the eyes if taken as adjunctive treatment to artificial tears and other medications.

7. Bone health

Cod liver is rich in vitamin D, which is essential for bone health and may help reduce the bone loss that comes with aging. Vitamin D helps the body absorb calcium, which also plays a crucial role in maintaining strong bones.

8. Joint health

Rheumatoid arthritis is a chronic, progressive, autoimmune disease characterized by joint pain, kidney problems, and heart issues. Studies have suggested that fish oils may reduce some of the symptoms of rheumatoid arthritis and the reliance on nonsteroidal anti-inflammatory drugs and corticosteroids.

9. Stomach ulcers

Stomach ulcers can cause symptoms such as abdominal pain and nausea. Animal studies have shown that cod liver oil may have positive effects in healing ulcers and reducing symptoms. However, more human studies are needed to determine whether cod liver oil has similar effects in humans.

10. Anxiety and depression

Research studies have long suggested that there may be a link between inflammation and mental health issues like anxiety and depression. Because cod liver oil is rich in omega-3 fatty acids, which lower inflammation, it may help reduce symptoms of anxiety and depression. 

One meta-analysis of 26 studies found a 17% lower risk of depression in those who had adequate fatty fish intake. Other reviews, however, have found insufficient evidence to determine whether omega-3s (1,000 to 6,600 mg per day of eicosapentaenoic and docosahexaenoic acids and other omega-3s) are effective in treating depression. More large-scale studies are needed.

Cod liver oil has been known to cause side effects in some people, such as:

• Heartburn and gastric distress
• Rashes after prolonged consumption

Additionally, cod liver oil can react with many medications and can cause dangerous side effects:

• Increased bleeding tendency and hemorrhage if taken with Coumadin (warfarin) and other anticoagulants
• Reduced vitamin E levels
• Other drug interactions, such as contraceptive pills and cod liver oil can blunt the cardiovascular benefits of fish oils, and taking fish oil with weight-loss drugs, such as orlistat, might decrease the absorption of fish oil fatty acids

Because cod liver oil is rich in vitamin A, consuming high amounts of cod liver oil can cause excess accumulation of vitamin A in the liver, leading to liver cell injury or even nonalcoholic fatty liver disease. 

The safe dose of cod liver oil in adults is 15-20 mL orally daily for up to 4 months. However, as with any supplement, talk to your doctor before incorporating cod liver oil into your diet or supplement regimen.