Omega-3 fatty acids are essential nutrients that play a crucial role in maintaining overall health and well-being. EPA stands out among the various types of omega-3s for its numerous health benefits. Understanding the importance of EPA and how to incorporate it into the diet can have significant health benefits. In this article, we will explore the role of EPA in promoting overall well-being and how you can ensure you are meeting your EPA needs for optimal health.


What is EPA? 

Many do not understand dietary fats’ crucial role in health and wellness. Fatty acids, for example, are involved with the expression of transcription factors and metabolic processes. They are also required for central nervous system function and essential to forming lipid bilayers of cells and organelles. The fatty acid composition of cellular membranes will significantly impact their fluidity and permeability and, therefore, the function of the proteins among them. Fatty acids vary based on length, degree of saturation, and hydroxylation, which impacts their properties and functions in the body.

BLOG: What are the Symtoms of Lack of Omega-3

Polyunsaturated fatty acids are fatty acids that contain two or more double bonds in the carbon chain. Furthermore, they are classified based on the location of their first double bond closest to the omega methyl group. Therefore, omega-3 fatty acids are polyunsaturated fatty acids with a double bond located at three carbons from the methyl end of the carbon chain.

Eicosapentaenoic acid (EPA) is a long-chain omega-3 polyunsaturated fatty acid containing 20 carbons and five double bonds. It is one of several omega-3 fatty acids, yet its distinctive chemical structure allows it to support health in unique ways. EPA and other omega-3 fats are considered essential fatty acids because the human body cannot make them on its own, so we must obtain them from our diet. However, EPA is not found in many foods.


Where Does It Come From?

Omega-3 fats, like EPA, are initially synthesized in marine microalgae and build up in the fat of fish through the marine food chain. Cold water fatty fish are considered the best sources of omega-3 fats EPA and docosahexaenoic acid (DHA). Some food sources noted to have high levels of EPA include:

  • Herring (0.77 g EPA per 3 ounces cooked)
  • Farmed salmon (0.59 g EPA per 3 ounces cooked)
  • Sardines, canned (0.45 g EPA per 3 ounces drained)
  • Mackerel (0.43 g EPA per 3 ounces cooked)

Some claim that EPA and DHA needs can be met through adequate intake of alpha-linolenic acid (ALA), which can be converted in limited amounts into EPA and DHA. ALA is found in various foods, including soybean, flaxseed, chia, hemp, and canola oils. However, the conversion of ALA into EPA and DHA is minimal. Therefore, it should not be considered a replacement for direct consumption of EPA and DHA.

BLOG: What is Omega-3 EPA?

For some people, regular fish intake is not a realistic option. For others, it may not be possible at all. Thus, EPA can also be obtained through supplementation (fish or algal oil). Once ingested, EPA, like other polyunsaturated fatty acids, is incorporated into cellular membranes, where it can affect cellular functions.


What is EPA’s role in the body?

Omega-3 polyunsaturated fatty acids are known for playing diverse roles in human health and have been the focus of much research. Most research has been conducted on EPA + DHA combined, including supplementation or fish intake. Still, some researchers have sought to test and understand the health effects of the two separately. Some of the health benefits of EPA include:

Brain health and neurodegenerative diseases: Research shows that increasing intake of EPA and other omega-3 fatty acids alters the composition of fatty acids in the brain’s cellular membranes and plays crucial roles in brain health and function. Accumulating evidence demonstrates that omega-3 fats, like EPA, play an important role in neurodegenerative disorders, including Parkinson’s, Multiple sclerosis, dementia, depression, and Alzheimer’s disease. Furthermore, research has revealed different mechanisms of EPA and DHA and demonstrated that EPA is more powerful than DHA in relieving symptoms in the treatment of clinical depression.

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Cardiovascular health: For decades, it’s been noted that populations around the globe with greater fish intake have a lower risk of coronary heart disease. Observational studies have reported inverse associations between the consumption of fatty fish or omega-3 fatty acids and atherosclerotic cardiovascular disease and cardiovascular disease risk. While there are plenty of mechanisms through which omega-3 affects cardiovascular risk, EPA appears explicitly to reduce several inflammatory markers, improve endothelial function and membrane stability, and stabilize or reduce atherosclerotic plaque. The JELIS, REDUCE-IT, and RESPECT-EPA trials of pure EPA have all demonstrated cardiovascular benefits.

Inflammation: Oxidative stress and chronic inflammation contribute to the risk of disease, and elevated levels of inflammatory markers are seen in those with non-communicable diseases. Polyunsaturated fatty acids, like EPA, have a range of anti-inflammatory effects, such as decreasing the production of inflammatory eicosanoids, cytokines, chemokines, and acute-phase proteins. For example, research in human studies demonstrates an inverse association between EPA and DHA status and blood markers of C-reactive protein, IL-6, and more.


How to Test EPA

Current dietary guidelines for Americans recommend consuming ~8 ounces of seafood per week to obtain an average daily intake of ~250mg of EPA and DHA. However, mounting evidence indicates that higher doses of omega-3s are more likely to provide clinical benefit. For example, the OMEGA-REMODEL study found that 4g of EPA + DHA daily for six months improved clinical outcomes after acute myocardial infarction.

Similarly, other studies found that 4g per day improved arterial dilation and significantly reduced triglyceride levels. Yet, as research develops, it’s becoming more and more apparent that omega-3 intake may not be the most critical number to be tracked because individual intake does not always align with blood levels. Genetics may even play a role in a person’s utilization of omega-3 fats. Therefore, many experts agree that omega-3 status should be determined by measuring Omega-3 Index instead of omega-3 intake.

BLOG: Are there Any Side Effects of Omega-3?

The Omega-3 Index measures the amount of EPA and DHA in the red blood cell membranes expressed as a percentage. Rather than considering daily intake of omega-3s, the Omega-3 Index is a method for evaluating long-term omega-3 status. Evidence indicates an increased risk of coronary heart disease risk when the the Omega-3 Index is less than 4% and a decreased risk when it is above 8%.

Furthermore, a 2023 meta-analysis found that omega-3 supplementation did not significantly improve measures of cognition, but a higher baseline Omega-3 Index and higher Omega-3 Index increments were associated with improved cognitive function in older adults. For this reason, the Omega-3 Index is likely a better indicator of EPA + DHA status vs. relying only on monitoring omega-3 intake on a regular basis.



Omega-3 fats play an essential role in overall health and well-being. While there are several types of omega-3 fatty acids, EPA, with its unique chemical structure and physiological function provides exclusive health benefits. EPA impacts brain health, neurodegenerative disease, cardiovascular health, chronic inflammation, and more. The main sources of EPA include fatty cold-water fish such as herring, salmon, sardines, and mackerel, as well as fish or algal oil supplementation.

Still, many people do not consume enough fish to meet the levels of EPA that can provide clinical health benefits. Even more so, dietary intake is not always associated with omega-3 status in the blood. Therefore, more recent evidence suggests that individuals should assess their omega-3 status by testing their Omega-3 Index rather than relying soley on montitoring their omega-3 intake.

These statements have not been evaluated by the Food and Drug Administration. This test is not intended to diagnose, treat, cure, prevent or mitigate any disease. This site does not offer medical advice, and nothing contained herein is intended to establish a doctor/patient relationship. OmegaQuant, LLC is regulated under the Clinical Laboratory improvement Amendments of 1988 (CLIA) and is qualified to perform high complexity clinical testing. The performance characteristics of this test were determined by OmegaQuant, LLC. It has not been cleared or approved by the U.S. Food and Drug Administration.

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