Can Omega-3 Fatty Acids Lower Cholesterol and Triglycerides?

Omega-3 fatty acids can lower your cholesterol and triglyceride levels. You can incorporate omega-3s into your diet by eating certain kinds of fish and nuts, or by taking supplements containing these healthy compounds, including fish oil.

Considered "healthy fats," omega-3 fatty acids may also provide other heart-healthy benefits and even prevent cardiovascular disease.

omega 3 sources

What Are Omega-3 Fatty Acids?

Omega-3 fatty acids are types of polyunsaturated fats found in fatty fish, plant-based sources, and certain supplements. These fats include:

  • Alpha-linolenic acid (ALA)
  • Docosahexaenoic acid (DHA)
  • Eicosapentaenoic acid (EPA)

ALA is available as a supplement, but can also be found in a variety of plant products, including seeds (especially chia seeds and flaxseed), soybeans, and nuts.

EPA and DHA are commonly found in the following foods:

  • Fatty fish: Including anchovies, salmon, tuna, halibut, herring, and sardines
  • Nuts: Including walnuts and almonds
  • Supplements: Including fish oil, cod liver oil, and krill oil (these typically contain varying amounts of both EPA and DHA)

All three types of omega-3s are referred to as “healthy fats” because they do not appear to promote atherosclerosis, known for causing heart disease. However, studies have primarily examined the effect that DHA and EPA have on the reduction of lipids and lowered risk of cardiovascular disease. ALA continues to be studied and may be less effective.

How Do Omega-3s Affect Lipids?

DHA and EPA have been primarily studied when looking at the effect that omega-3 fats have on lipid levels. The usual doses of EPA and DHA used in these studies ranged between 250 milligrams (mg) and 500 mg to 5 grams per day. However, there is no recommended daily dose for either.

In order to achieve the amounts noted by researchers, you would need to consume a lot of fatty fish, nuts, seeds, and other foods containing these fats. Supplements can be used to bring more omega-3 fats into your diet and help achieve the target amount. Overall, omega-3 fats appear to have a favorable impact on your lipid levels.

Omega-3 fats have a notable effect on triglyceride levels:

  • One study showed that ingesting 900 mg of omega-3 fatty acids each day resulted in a 4% decrease in triglyceride levels after about six months.
  • The most effective dose of omega-3s used in most studies was between 2 and 4 grams. This resulted in a drop in triglycerides between 25% and 45%.
  • The effectiveness of omega-3 fatty acids on triglycerides appears to be dose-dependent. This means that the more omega-3 fatty acids ingested, the lower your triglyceride levels will fall.
  • Omega-3 fatty acids seem to affect recently ingested triglycerides and work best when following a healthy diet.
  • Individuals with extremely high triglyceride levels (greater than 500 mg/dL) appear to get the most benefit from omega-3 fatty acid supplementation.

Although EPA- and DHA-containing products can lower triglyceride levels, they may affect other parts of your lipid profile as well:

  • Omega-3 fats can slightly raise your low-density lipoprotein (LDL) cholesterol. This change, however, is modest and ranges from 3% to 10%.
  • Omega-3 fats—despite increasing your LDL—also increase the size of your LDL. Smaller LDL particles can increase your risk of developing atherosclerosis, whereas larger LDL particles are considered beneficial for your heart health.
  • Consuming omega-3 fatty acids also appears to slightly increase high-density lipoprotein (HDL) levels.

Heart-Healthy Benefits of Omega-3 Fats

Besides having a favorable effect on your lipid profile, omega-3 fats also have a positive impact on other aspects of your heart health:

  • Omega-3 fats appear to help keep your heart beating at a normal rate. This is important for patients at risk of a heart attack because arrhythmias are the leading cause of cardiac deaths in the United States.
  • Omega-3 fats may improve the function of blood vessels.
  • Omega-3 fats may lower blood pressure and heart rate.
  • Omega-3 fats may reduce inflammation at larger doses.
  • Studies have shown that individuals with cardiovascular disease who consume fish oil may have a decreased risk of sudden death and death due to cardiovascular disease.

Daily Intake

Omega-3 fatty acids are available in a variety of foods and supplements, including fish oil. Studies have found that the DHA and EPA found in fish oil can produce favorable changes in several risk factors for cardiovascular diseases, though fresh fish is more effective. 

Some experts, including the American Heart Association, recommend eating one to two servings of fatty fish per week. One serving consists of 3 1/2 ounces of cooked fish.

If you don't like eating fish, a fish oil supplement containing about 1 gram of omega-3 fats is an alternative. However, you should not increase your dose further without consulting with your healthcare provider. High doses of omega-3 fatty acids may affect blood platelet levels, causing a person to bleed and bruise more easily.

Prescription vs. OTC Supplements

Prescription omega-3 fatty acids contain a certain amount of natural or modified forms of omega-3 fatty acids. They are purified and are thoroughly rid of impurities such as trans-fats, mercury, or other contaminants.

Prescription omega-3 fatty acids are usually taken by individuals with very high triglyceride levels who are in need of larger doses of omega-3 fats to bring their triglycerides down.

Supplements that are available over-the-counter (OTC) are classified as “foods” by the U.S. Food and Drug Administration (FDA). Therefore, they do not have to undergo the rigorous purification processes or efficacy studies that prescription drugs have to go through.

A Word From Verywell

The evidence does show that incorporating omega-3 fatty acids into your diet can have a positive impact on your cholesterol levels. The best source is fresh fish and other foods that naturally contain these healthy fats.

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Article Sources
Verywell Health uses only high-quality sources, including peer-reviewed studies, to support the facts within our articles. Read our editorial process to learn more about how we fact-check and keep our content accurate, reliable, and trustworthy.
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  6. American Heart Association. Fish and omega-3 fatty acids. Updated March 23, 2017.

Additional Reading
  • American Heart Association. Fish and omega-3 fatty acids. 2017.

  • Dipiro JT, Talbert RL. Pharmacotherapy: A Pathophysiologic Approach. 10th ed. New York, NY: McGraw-Hill Education; 2017.