There is no evidence that fish oil is good for lowering high cholesterol. In fact, some studies show that fish oil can increase low density lipoprotein (LDL), or “bad” cholesterol.
This finding comes from a review in Pharmacy and Therapeutics.
The relationship between diet, cholesterol, and disease is complex. While fish oil can improve heart health for some people, a person with high LDL cholesterol may have to opt for other forms of omega-3.
In this article, we’ll take a closer look at whether people should take fish oil for cholesterol, other ways to benefit from omega-3s, and other approaches to lowering cholesterol.
Fish oil is a fat that comes from oily fish like herring, mackerel, and salmon. It is available as a liquid or in capsules. People can also get it from their diet.
Many people take fish oil as a supplement because of its omega-3 content. Omega-3 fatty acids are linked to a number of health benefits, including:
- Lowering the likelihood of heart disease
- slight improvement in rheumatoid arthritis symptoms
- Supporting the growth of a fetus during pregnancy
There are three main types of omega-3s. Everyone has a different effect on the body. You are:
- Eicosapentaenoic acid (EPA)
- Docosahexaenoic acid (DHA)
- Alpha Linolenic Acid (ALA)
Fish oil contains mostly EPA and DHA, although the exact dosages can vary significantly depending on the type of fish the oil is from, as well as the brand or manufacturer.
Fish oil supplements don’t seem to lower high cholesterol.
There are two types of cholesterol: LDL or “bad” cholesterol and high-density lipoprotein (HDL) or “good” cholesterol.
In an older meta-analysis of 21 studies, researchers found that supplementing with fish oil was not helpful for those with high LDL cholesterol. In one study, fish oil raised LDL cholesterol levels.
When the researchers individually tested the specific omega-3 fatty acids found in fish oil, they found that EPA did not affect cholesterol levels, but DHA increased them.
This suggests that fish oil may not be beneficial for people with high cholesterol.
However, fish oil also increases the levels of high density lipoprotein (HDL), or “good” cholesterol, in the body and increases the size of the LDL particles. This is beneficial because smaller LDL particles are associated with a higher risk of atherosclerosis, which can lead to angina and heart attacks.
Because of the conflicting evidence, people who are concerned about their LDL cholesterol levels may be best to look for other ways to lower them.
There are a number of effective ways to lower cholesterol. These include:
The Centers for Disease Control and Prevention (CDC) state that diet is one of the factors that contribute to a person’s risk for cardiovascular disease.
People with high cholesterol may need to avoid saturated fat. Common sources are:
- Palm oil
- fatty cuts of meat
- Dairy products like cheese
People can take steps to avoid these products and prioritize healthy alternatives instead. The CDC recommends eating more:
- fruits and vegetables
- Whole grains like oats
- Beans and legumes
- lean meat like chicken
- fish and seafood
- low fat dairy
- unsaturated fats like olive oil or avocado oil
Learn about foods you should avoid and include for high cholesterol.
A person can also lower their cholesterol through a number of lifestyle changes. These include:
- get regular exercise
- stop smoking
- Limitation of alcohol
- Achieving or maintaining a moderate body weight
These can be big changes, but it can be helpful to start small and gradually work towards these goals. The CDC suggests exercising with the family, incorporating exercise into everyday life and, if possible, working with a doctor to create a diet and fitness plan.
People with high cholesterol may need medication. The most common drugs are statins.
Some people hesitate to take statins. However, a 2018 review found that most people tolerate them well and that they are effective in lowering cholesterol and lowering the risk of death.
Learn more about the uses and risks of statins.
While fish oil supplements may not help people with high cholesterol, there are other forms of omega-3 that they can benefit from. These include:
EPA can lower the level of triglycerides in the blood. Triglycerides are a type of fat. High levels of triglycerides, or hypertriglyceridemia, are linked to a number of diseases, including:
EPA products can help people with high triglyceride levels, whether or not they also have high cholesterol.
The Food and Drug Administration (FDA) has approved several omega-3 products for medical use, some of which contain only EPA. These products require a prescription. People can take them with statins, a drug that lowers cholesterol.
Alternatively, people can only buy EPA supplements. However, it is best to speak to a doctor about this as the quality and effectiveness of these supplements can vary.
ALA is a type of omega-3 that comes from plant foods, such as:
- Nuts like walnuts
- Seeds like flax, chia, and hemp
- Vegetable oils such as rapeseed, soybeans, and flax
- Some vegetables like edamame beans
Researchers know less about the benefits of ALA than they do about other types of omega-3s. However, a 2013 review stated that people should include it as part of a balanced diet.
For most people, it is beneficial to consume oily fish. The U.S. Department of Agriculture’s Food Guidelines for Americans 2020-2025 recommend that most adults eat at least 8 ounces of low-mercury seafood each week.
On average, this gives someone 250 milligrams of DHA and EPA per day, although the exact amount will depend on the type of fish.
Because some seafood contains cholesterol from food, people who have difficulty controlling their cholesterol may need to be more careful.
UK charity Heart UK recommends people with this problem speak to a nutritionist about what is best for them.
Fish oil is not an effective treatment for high cholesterol. In some cases, the DHA in fish oil appears to increase LDL cholesterol. Hence, people who are concerned about high cholesterol should not rely on it.
However, many people can still eat fish and seafood in moderate amounts or get other health benefits from other forms of omega-3s such as EPA or ALA.
People looking to lower their cholesterol levels can speak to a doctor about diet and lifestyle changes, or trying a medication.