Omega-3 Fish Oil: Beyond EPA and DHA

Among supplement-takers, it’s not unusual for omega-3 fish oils to be part of a well-rounded wellness routine. There are several reasons for this. Omega-3 fatty acids have been extensively studied for their role in supporting cardiovascular health, brain function, cognition, mood, and healthy inflammatory responses.

Additionally, healthcare practitioners frequently recommend omega-3 supplementation because many people don't consume enough omega-3-rich foods, such as fatty fish, regularly. For those looking to support overall wellness, omega-3 fish oils check many boxes.

While there are numerous fish oil formulations available, not all products are created equal. In fact, many consumers spend considerable time comparing EPA and DHA content without realizing that there is a third omega-3 fatty acid that may also deserve attention: DPA.

What Are Omega-3 Fatty Acids?

Omega-3 fatty acids are a group of polyunsaturated fats that play important roles throughout the body. They are considered essential nutrients because humans cannot efficiently produce enough omega-3’s on their own and must obtain them through the diet or supplementation.

The three primary omega-3 fatty acids discussed in fish oils are EPA (eicosapentaenoic acid), DHA (docosahexaenoic acid), and the lesser-known DPA (docosapentaenoic acid). These fatty acids are naturally found together in fish and seafood, where they exist as part of a complex nutritional matrix. Although they share similar chemical structures, each omega-3 has unique properties and functions within the body.

The Omega-3 Family: EPA, DHA, and DPA

When most people think about omega-3 fish oil benefits, EPA and DHA typically receive the most attention.

EPA: Inflammation and Cardiovascular Support

EPA is perhaps most well-known for its role in supporting a healthy inflammatory balance. It serves as a precursor for signaling molecules that help regulate inflammatory processes throughout the body. Because of these effects, EPA has been extensively studied for its role in cardiovascular health and healthy aging.

DHA: The Structural Omega-3

DHA is a major structural component of the brain, nervous system, and retina of the eye. The brain contains particularly high concentrations of DHA, making it essential for maintaining healthy cell membranes and communication between cells. It has also been widely studied for its role in cognitive function, visual health, and healthy brain aging.

DPA: The Overlooked Middle Child

DPA receives far less attention than EPA and DHA despite being naturally present in fish. Positioned chemically between EPA and DHA, DPA has unique characteristics that distinguish it from both. Researchers have discovered that DPA may serve as a reservoir omega-3, capable of being converted into EPA or DHA when needed. This flexibility suggests that DPA may help support the body’s ability to maintain a balanced omega-3 status. Yet despite its presence in nature, DPA is often missing—or present only in very small amounts—in many concentrated fish oil supplements.

Why Most Fish Oils Focus on EPA and DHA

If fish naturally contain EPA, DHA, and DPA, why do many supplements focus almost exclusively on EPA and DHA?

Part of the answer lies in the history of omega-3 research. Early studies of populations with high fish consumption drew attention to the potential health benefits associated with omega-3 fatty acids. As scientists investigated these effects more closely, EPA and DHA emerged as two of the most extensively studied omega-3’s, leading them to become the primary focus of both research and supplement development.

As consumer interest in omega-3’s grew, manufacturers began developing products with increasingly higher concentrations of EPA and DHA. This emphasis helped establish EPA and DHA as the omega-3’s most consumers recognize today, while other naturally occurring fatty acids, such as DPA, received comparatively little attention.

The Missing Piece: What is DPA?

For years, DPA received relatively little scientific attention compared with EPA and DHA. More recently, researchers have begun exploring its unique biological functions. DPA appears to participate in several important physiological processes, including the production of specialized lipid mediators involved in inflammatory regulation and cellular signaling. Researchers have also observed that populations with higher seafood consumption often have measurable levels of DPA in their tissues, raising questions about whether DPA may contribute to some of the observed benefits associated with fish-rich dietary patterns.

One of DPA's most intriguing characteristics is its versatility. Unlike EPA and DHA, which generally perform distinct functions, DPA can move in both directions along the omega-3 pathway. It can be converted into EPA or DHA as needed, potentially helping the body maintain balance among these important fatty acids. Some researchers have even proposed that DPA serves as a metabolic bridge between EPA and DHA. While research on DPA continues to evolve, its emerging role highlights an important point: fish naturally provide more than just EPA and DHA.

Full-Spectrum Fish Oil vs. Concentrated Fish Oil

Full-spectrum fish oils aim to preserve the natural fatty acid profile found in fish as closely as possible. Rather than selectively concentrating one or two fatty acids, these formulations maintain a broader range of naturally occurring marine lipids, including EPA, DHA, DPA, and other beneficial fatty acids. This approach more closely reflects how omega-3’s are consumed in whole-food dietary patterns.

Concentrated fish oils, on the other hand, are designed to maximize the amount of EPA and/or DHA per serving. While this can result in higher levels of specific omega-3’s, the concentration process may alter the natural balance of fatty acids found in fish and often reduces the presence of lesser-known compounds such as DPA.

As research continues to explore the unique roles of individual omega-3 fatty acids, there is growing interest in the potential benefits of preserving the full spectrum of marine lipids rather than focusing exclusively on EPA and DHA. For consumers seeking an omega-3 supplement that more closely mirrors the composition of whole fish, a full-spectrum fish oil may be worth considering.

Choosing an Omega-3 Fish Oil Supplement

When evaluating omega-3 fish oil capsules, it can be helpful to look beyond EPA and DHA numbers alone.

Consider the following questions:

• Does it provide a broad spectrum of omega-3’s? Some products contain only highly concentrated EPA and DHA, while others preserve a wider range of naturally occurring fatty acids, including DPA.
• What form are the omega-3’s in? Fish oils naturally contain omega-3’s in triglyceride form. Some concentrated products convert these fats into different molecular forms during processing. Many consumers prefer triglyceride-form fish oils because they more closely resemble the fats found in whole fish.
• Is the source transparent? Look for companies that provide information about sourcing, sustainability, and quality testing.
• Has the oil been protected from oxidation? Omega-3 fatty acids are sensitive compounds. Proper manufacturing, storage, and testing help ensure product quality and freshness.

The Bottom Line

Omega-3 fish oil remains one of the most widely used and extensively researched dietary supplements available today. Most conversations about omega-3’s focus on EPA and DHA—and for good reason. Both play important roles in supporting overall health and wellness. However, they are not the entire story.

Fish naturally contain a spectrum of omega-3 fatty acids, including DPA, a lesser-known fatty acid that is gaining increasing scientific attention. As researchers continue to explore its unique biological functions, DPA is emerging as a significant member of the omega-3 family, rather than simply serving as an intermediary between EPA and DHA.

When choosing an omega-3 fish oil supplement, looking beyond headline EPA and DHA numbers may provide a more complete picture of what a product offers. After all, nature rarely works through a single nutrient in isolation—and omega-3’s are no exception.

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