Both cod liver oil and fish oil are oils derived from fish. It is an excellent source of omega-3 fatty acids, which can reduce the risk of chronic diseases.
Although cod liver oil is a type of fish oil, what is commonly called “fish oil” comes from various sources.
There are some differences between cod liver oil and fish oil. For example, they contain different levels of omega-3 fatty acids and different vitamins.
This article describes the differences between cod liver oil and fish oil. It lists the benefits and risks of each, and ways in which a person can include them in their diet, through food or supplements.
Both cod liver oil and fish oil are sources of omega-3s. Omega-3s are a group of fatty acids that, in small doses, are important for human health.
Most studies focus on three types of omega-3s: alpha-linolenic acid (ALA), docosahexaenoic acid (DHA) and eicosapentaenoic acid (EPA). The benefits of each acid can vary slightly, so getting all three can improve health.
A person should get these acids from the diet; the body does not make them. ALA converts to EPA and then DHA, but the conversion rate is low. To get optimal Omega-3 benefits, one needs to take DHA and EPA.
Cod liver oil is a type of fish oil. The main differences between cod liver oil and other fish oils include:
- Different vitamins: Cod liver oil contains vitamins A and D.
- Omega-3 content: Cod liver oil comes from the liver of the cod fish, which is less fatty than other fish, such as tuna and mackerel. For this reason, cod liver oil provides a lower dose of omega-3s.
- Other health benefits: In addition to the supposed benefits of omega-3s, cod liver oil has long been a popular remedy for managing constipation and
causes labor.
While cod liver oil is a type of fish oil, people usually use the term “fish oil” to refer to fatter fish oil, such as that of tuna and mackerel.
Some research shows that omega-3s can improve heart health by lowering blood pressure or reducing the risk of a heart attack. Most such research has focused on populations with a lot of fish oil in their diet, not people who supplement fish oil.
Not all research supports these potential benefits.
Omega-3 supplements, including fish oil, can also:
Researchers continue to study omega-3s for a wide range of conditions, but the data so far are unconvincing. For example, a meta-analysis of omega-3s in 2019 suggests that it may improve symptoms of depression, but other studies are unconvincing or undermining it.
Like other fish oils, cod liver oil can reduce the risk of medical conditions.
The study also found that cod liver oil users had more health problems, and that they were more likely to report bone disease and benign growth.
The authors of the study suggest that people with health problems are more likely to take cod liver oil. In addition, they found that cod liver oil users have healthier lifestyles, suggesting that other differences may explain the different health outcomes between the groups.
Vitamin D plays an important role in health. About a quarter of Americans
- reduces the risk of osteoporosis, especially if someone takes it with calcium
- reduces the risk of developing certain types of crops
- improving the health of the immune system
- supports glucose metabolism
Read more here about the benefits of fish oil.
Because cod liver oil and fish oil are both fish oils that contain omega-3 fatty acids, the risks are similar. These include:
- Fish allergies: Fish oil supplements can cause some fish allergies. In some people, the reaction can be severe.
- Stomach issues: Some people who take fish oil supplements experience stomach problems such as bloating, gas, diarrhea or constipation.
- Bad taste: Fish oil can leave a foul taste in the mouth, and someone may notice bad breath immediately after taking the supplement.
- Blood pressure:
Limited research suggests that omega-3s may lower blood pressure. People who use blood pressure medication should talk to a doctor before trying these supplements. - Blood clotting: Omega-3s can also affect blood clotting, so people with clotting disorders, bleeding disorders and those using clotting medication should talk to a doctor before refilling fish oil.
- Interactions with other drugs: Doctors have not identified all possible drug interactions related to fish oil, so people taking any medicine that is essential for their health should talk to a doctor before taking any supplements.
There are three main types of cod liver oil and fish oil supplements:
Kos
A person can get cod liver oil by eating cod. A number of foods, including most fish, are good sources of omega-3 fatty acids and can provide benefits for supplements. Fatty fish such as tuna and mackerel are the highest in omega-3s.
Oils
A number of manufacturers make pure fish oil formulas, or fish oils that contain other supplements. These oils usually contain higher concentrations of fish oil, but can taste bad.
Pills
Capsules with fish oil may be a more palatable option for people who do not want to use oily supplements.
Alternatives
Vegans and vegetarians may not want to eat fish oil. Flaxseed oil contains omega-3s, but not the EPA and DHA in fish oil. Algae oil contains DHA, but not EPA.
The latest review by the Institute of Medicine to determine the right dose of omega-3s is based on unconvincing data. Instead, the organization looked at average intakes in healthy groups and recommended the following daily intakes:
Eating two to three servings of fish a week can help someone get the recommended amount of omega-3s.
Supplements vary in the amount of omega-3s as well as the type of omega-3s. It is important to check the label. Users should also look for other ingredients, as taking too many supplements can increase the risk of overdosing on a vitamin.
Most research shows that food is the healthier source of fish oil, and that the apparent benefits of omega-3s may be less clear when someone is taking supplements. For example, the cardiovascular benefits of omega-3s can only occur in people who eat omega-3 rich foods, not supplements.
Omega-3s from cod liver oil and fish oil can have important health benefits, and there is little evidence that they can harm healthy people.
Consider increasing the fish intake to get the most benefits. People interested in trying supplements should first talk to a doctor.
For those who do not want to eat fish products, there are other great sources of omega-3s, such as algal oil.