There is no evidence that fish oil can lower high cholesterol levels. In fact, some studies show that fish oil can elevate 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 may benefit heart health for some people, a person with high LDL cholesterol may need to opt for other forms of omega-3.

In this article, we will look more closely at whether people should take fish oil for cholesterol, other ways to benefit from omega-3, and other approaches to lowering cholesterol.

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Fish oil is a fat that comes from oily fish, such as herring, mackerel, and salmon. It is available as a liquid or in capsules. People can also obtain it from their diet.

Many people take fish oil as a supplement due to its omega-3 content. Omega-3 fatty acids are linked to a number of health benefits, including:

  • lowering the chances of heart disease
  • mildly improving the symptoms of rheumatoid arthritis
  • aiding the growth of a fetus during pregnancy

There are three main types of omega-3. Each has a different effect on the body. They are:

  • eicosapentaenoic acid (EPA)
  • docosahexaenoic acid (DHA)
  • alpha-linolenic acid (ALA)

Fish oil primarily contains EPA and DHA, though the exact dosages can vary considerably depending on what type of fish the oil came from, as well as the brand or manufacturer.

Fish oil supplements do not appear to lower high cholesterol levels.

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 fish oil supplementation did not help with high LDL cholesterol. In fact, in one study, fish oil raised LDL cholesterol levels.

When the researchers tested the specific omega-3 fatty acids contained in fish oil individually, they found that while EPA did not affect cholesterol levels, DHA increased them.

This suggests that fish oil may not be beneficial for those with high cholesterol.

However, fish oil also raises the levels of high-density lipoprotein (HDL) or “good” cholesterol in the body, and increases the size of LDL particles. This is beneficial, because smaller LDL particles are associated with a greater risk of atherosclerosis, which can contribute to angina and heart attacks.

Because of the conflicting evidence, it may be best for people who are concerned about their LDL cholesterol levels to look for other ways to lower it.

There are a number of effective ways to lower cholesterol. These include:

Dietary changes

The Centers for Disease Control and Prevention (CDC) state that diet is one of the factors that contributes to a person’s risk for cardiovascular disease.

People with high cholesterol may need to avoid saturated fat. Common sources include:

  • palm oil
  • fatty cuts of meat
  • dairy products, such as cheese

People can take steps to avoid these products and prioritize healthy alternatives instead. The CDC recommend eating more:

  • fruits and vegetables
  • whole grains, such as oats
  • beans and legumes
  • lean meats, such as chicken
  • fish and seafood
  • low-fat dairy
  • unsaturated fats, such as olive oil or avocado oil

Learn more about foods to avoid and include for high cholesterol.

Lifestyle changes

A person can also lower their cholesterol with a number of lifestyle changes. These include:

  • getting regular exercise
  • stopping smoking
  • limiting alcohol
  • reaching or maintaining a moderate body weight

These can be big changes, but starting small and working towards these goals gradually can help. The CDC suggest exercising with family, incorporating movements into one’s daily routine, and working with a doctor to create a diet and fitness plan, if possible.

Medication

People with high cholesterol may require medication. The most common medications are statins.

Some people feel reluctant to take statins. However, a 2018 review states that most people tolerate them well, and that they effectively decrease cholesterol levels and lower 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 may benefit from. These include:

EPA

EPA can lower blood triglyceride levels. Triglycerides are a type of fat. High triglyceride levels, or hypertriglyceridemia, is associated with 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) have approved several omega-3 products for medical use, some of which only contain EPA. These products are available by prescription. People can take them alongside statins, a drug that lowers cholesterol levels.

Alternatively, people can purchase EPA-only supplements. However, it is best to speak with a doctor about this, as the quality and potency of these supplements can vary.

ALA

ALA is a type of omega-3 that comes from plant foods, such as:

  • nuts, such as walnuts
  • seeds such as flax, chia, and hemp
  • plant oils, such as those made from canola, soybean, and flax
  • some vegetables, such as edamame beans

Researchers know less about the benefits of ALA than they do other types of omega-3. However, a 2013 review states that people should include it as part of a balanced diet.

For most people, it is beneficial to consume oily fish. The United States Department of Agriculture’s Dietary Guidelines for Americans 2020–2025 recommends that most adults eat at least 8 ounces of low-mercury fish and seafood each week.

On average, this gives someone 250 milligrams of DHA and EPA per day, though the exact amount will depend on the type of fish.

However, because some fish and seafood contains dietary cholesterol, people who struggle to control their cholesterol levels may need to be more cautious.

The United Kingdom charity, Heart UK, recommends that people with this concern speak with a dietitian 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 raise LDL cholesterol. As a result, people who are concerned about elevated cholesterol should not rely on it.

However, many people can still eat fish and seafood in moderate amounts, or obtain other health benefits from other forms of omega-3, such as EPA or ALA.

People who want to lower their cholesterol can speak with a doctor about making dietary and lifestyle changes, or about trying a medication.