As sunshine is the main source of vitamin D, a significant number of people should consider switching from fish oil in the warm weather months — when they tend to have more sun exposure — to cod liver oil in the cool weather months, when their sun exposure is minimal. However, many people don’t get enough sun exposure even in warm weather months, meaning their vitamin D levels may still be too low in summer … they would therefore benefit from cod liver oil even in warm weather months.
Osteoarthritis, the breakdown of the cartilage that cushions the joints, causes pain and stiffness in millions of people, as they grow older. Fish oil, rich in omega-3 fats, helps counter inflammation, so some people with another form of arthritis, rheumatoid arthritis (an inflammatory disease), take fish oil supplements to help re-duce symptoms. There is also an inflammatory element in osteoarthritis, but this is apparently the first study to look at fish oil’s effect on the disease in humans.
The omega-3 fatty acids in fish oil help to balance the omega-6 fatty acids, which are found mostly in vegetable oils. When these two groups of fatty acids are out of balance, the body releases chemicals that promote inflammation. People appear to produce more of these inflammatory chemicals when experiencing psychological stress (e.g., academic examinations). With a fatty acid imbalance, inflammatory response to stress appears to be amplified.
Sources of cod liver oil
EPA and DHA are found in mackerel, salmon, herring, sardines, sablefish (black cod), anchovies, albacore tuna, and wild game. Cod liver oil contains large amounts of EPA and DHA. Fish oil supplements typically contain 18% EPA and 12% DHA, though more purified (i.e., higher in EPA and DHA) fish oil supplements are sometimes available. In addition, DHA is available in a supplement that does not contain significant amounts of EPA.
What are the benefits of cod liver oil?
Benefits of the Omega-3 Found in Fish Oil and Cod Liver Oil
- Helps fight and prevent heart disease, cancer, depression, Alzheimer’s, arthritis, diabetes, ulcers, hyperactivity and many other diseases
- Increases your energy level and ability to concentrate
- Provides greater resistance to common illnesses such as flu and cold
- Helps pregnant women avoid premature births, low birth weight and other complications
Preliminary evidence also shows that omega-3 fatty acids from fish oil may help regulate the rhythm of the heart. EPA and DHA have been reported to help prevent cardiac arrhythmias.
Cod liver oil is effective in treating arthritis as well. Researchers funded by Great Britain’s Arthritis Research Campaign found that the elongated omega-3 fatty acids in cod liver oil reduce both pain and damage in inflamed joints.
Cod liver oil also reduces the generation of free radicals in the system and inflammatory processes as in arthritis or other inflammatory conditions.
EPA and DHA also have anti-inflammatory activity. As a result, fish oil is used to help people with various inflammatory conditions, such as Crohn’s disease and rheumatoid arthritis.
Symptoms of high intake
Though fish oil is rich in heart-healthy omega-3s, supplements can pose dangers. They can increase the risk of hemorrhagic stroke, and people taking anticoagulants should not take them. Large doses may suppress the immune system.
The American Heart Association does say that people with heart disease should consider taking the supplements, but only if they don’t eat enough fish and after consulting a doctor. Eating fish is a better option for most people.
Cod liver oil is made from livers, of course. The liver is a filter, so toxins (such as PCBs) get concentrated there. Thus cod liver oil is more likely to be contaminated than other fish-oil supplements.
Most researchers studying the effects of EPA and DHA in humans who have a variety of health conditions have given those people at least 3 grams of the total of EPA plus DHA—an amount that may require 10 grams of fish oil, because most fish oil contains only 18% EPA and 12% DHA.
In one trial, the maximum amount of fish oil tolerated by people being treated for cancer-related weight loss was reported to be approximately 21 grams per day. However, in people who do not have cancer, the maximum tolerated amount may be different.
Pregnant women should limit their intake of vitamin A (which is in cod liver oil). Not for those with diabetes except on the advice of their physician.