By Jordan Casey, MS, Functional Medicine Practitioner
For years, omega-3s like EPA and DHA have been marketed as the foundational solution for inflammation support.
The supplement industry quickly latched on and ran with it: “Higher doses. Isolating compounds. More EPA. More DHA. More = better.”
But emerging research suggests the role of omega-3s is far more nuanced than megadosed EPA and DHA. In fact, this is another quintessential example of ‘more is not always better.’ The type, form, and context of omega-3s matter just as much, if not more, than the amount.
A 2022 narrative review examining various clinical trial outcomes on marine oils and immune regulation is undeniable. Instead of asking how much omega-3s “reduce inflammation,” it explores how whole-food-based and minimally processed marine oils interact to influence immune balance, inflammatory resolution, cardiovascular health, and autoimmune disease.
The takeaway is clear: not all omega-3 supplements are created equal.
Inflammation Is Not the Enemy — Unresolved Inflammation Is
Inflammation is often portrayed as something to suppress. But inflammation itself is protective. It is the immune system’s immediate response to injury or infection. Persistent low-grade inflammation is what poses risks to health. It plays a central role in cardiovascular disease, metabolic dysfunction, and immune imbalance [2].
What makes omega-3s biologically interesting is not that they blunt immune activity, but that they participate in the resolution phase of inflammation, in which the body turns off inflammatory signaling and restores balance [3].
EPA and DHA are the most prominent omega-3 fatty acids found in fish oils; they are also the most studied and recognized anti-inflammatory fatty acids. But several additional anti-inflammatory fatty acids are present in unprocessed marine oils [3].
How EPA and DHA Work
EPA and DHA are not just "fats"; they are structural signaling molecules that integrate into your cell membranes, dictating how your body handles stress and inflammation [4].
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DHA (Docosahexaenoic acid) is the primary structural component of the brain and retina, where it provides "membrane fluidity"—essential for making cellular receptors more sensitive to modulatory signals from molecules like insulin and neurotransmitters [5].
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EPA (Eicosapentaenoic acid) acts more as a regulator, competing at a cellular level with pro-inflammatory omega-6 fats to shift them from producing chemicals that drive low-grade inflammation to producing anti-inflammatory molecules [3].
Collectively, EPA and DHA initiate an active biochemical cleanup process called efferocytosis, in which white blood cells stop attacking invaders/tissues and begin clearing cellular debris. This allows the body to transition from a defensive inflammatory state back to a state of repair and balance [6].
The most sophisticated role of these fatty acids is their conversion into Specialized Pro-resolving Mediators (SPMs), such as resolvins and protectins. These molecules are involved in the active termination of inflammation and the promotion of tissue repair. EPA and DHA provide the necessary precursors for these pro-resolving mediators to function efficiently [7].
Cardiovascular Outcomes from Omega-3s: Why Results Have Been Mixed
Clinical trials examining omega-3 supplementation and cardiovascular outcomes have produced varying results. Some show reductions in major adverse cardiovascular events, including myocardial infarction and cardiovascular death. Others show smaller or nonsignificant changes.
One explanation discussed in the literature is formulation variability [8].
Two supplements labeled “omega-3” may differ substantially in processing methods, fatty acid composition, and the presence or absence of additional marine-derived lipid compounds.
Highly purified oils or chemically concentrated EPA/DHA products are not biologically identical to minimally processed marine oils. When oils undergo extensive refining, certain naturally occurring fatty acids and lipid mediator precursors are degraded or removed altogether [9].
The Missing Pieces: Pro-Resolving Mediator Precursors
Newer research on the anti-inflammatory effects of omega-3s highlights compounds such as 7-hydroxy-docosahexaenoic acid (17-HDHA) and 18-hydroxy-eicosapentaenoic acid (18-HEPE). Each has been identified as an SPM [10].
The key takeaway is that these hydroxy-fatty acids (17-HDHA and 18-HEPE) are the "pre-activated" versions of omega-3s. Providing them directly allows the body to bypass several metabolic steps to initiate efferocytosis (cellular cleanup) more rapidly [11]. These compounds are derived from less recognized forms of omega-3s, eicosenoic acid (ESA) and docosapentaenoic acid (DPA) – both of which are naturally present in certain marine oils [12].
Processing methods such as bleaching, heating, and refining to strip marine oils down to isolated EPA/DHA reduce the levels of these additional bioactive lipid precursors. Minimally processed oils retain more of these naturally occurring components.
Beyond EPA and DHA: Why Broader Marine Oils Matter
Different fish species and environmental conditions influence fatty acid profiles of the oil. Oils derived from cold-water fish, for example, contain higher levels of SPM precursors than the same species caught in warmer regions [1].
Cod liver oil offers even further support beyond omega-3s and SPMs. In its traditional form, it delivers:
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EPA
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DHA
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DPA
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ESA
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Naturally occurring fat-soluble vitamin A
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Naturally occurring fat-soluble vitamin D
This combination offers a more physiologically coherent signal than isolated fatty acids and vitamins alone.
The Role of Vitamins A and D in Immune Calibration
Vitamins A and D both play essential roles in immune function. Vitamin D influences antimicrobial peptide production and immune cell activation. Vitamin A contributes to mucosal integrity, immune tolerance, and cellular differentiation.
The review discusses high-quality studies which show that when omega-3 fatty acids are delivered alongside vitamins A and D (in their natural or synthetic forms), the immune effects are more robust than when isolated fatty acids are taken alone [1]. Specifically, significant reductions in autoimmune disease risks were observed due to the immunomodulatory effect of this nutritional synergy [1].
In fact, one study highlighted in the review followed 25,871 participants taking 2000 IU of vitamin D and 1000 mg of omega-3 over roughly 5 years and observed a 22% lower risk of developing autoimmune disease [1, 13].
Traditional cod liver oil has a long history of use for immune health. This review of literature explains why it was a go-to staple in your grandmother's medicine cabinet.
What This Means for Cardiovascular and Immune Health
Cardiovascular disease is increasingly understood as an inflammatory condition of the vascular wall. Immune imbalance and unresolved inflammation are intertwined with plaque formation and instability.
Chronic immune dysregulation is also a central feature of autoimmune disease. Autoimmune disease rates continue to rise. While several dietary, lifestyle, and environmental factors are often involved in disease onset, the research is clear that this nutritional synergy offers immune support and protection [1].
The author suggests that this nutritional support is particularly relevant in early immune dysfunction, where inflammatory/autoantibody signaling may be mildly elevated before a formal diagnosis. Supporting resolution pathways at this stage may help restore immune balance before deeper dysregulation takes hold [1].
Omega-3 fatty acids and micronutrients certainly have a foundational role in health maintenance, but the conversation is shifting away from “how many grams of EPA/DHA should I take?” toward:
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How was the oil processed?
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Does it preserve immune-active lipid precursors?
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Is it delivered in a natural form?
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Does it include synergistic nutrients?
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Are the active ingredients naturally occurring or synthetic?
More Isn’t Always Better — Smarter is Better
The takeaway is not that concentrated omega-3 products are ineffective. It is that immune regulation is more complex than increasing a single fatty acid number.
Minimally processed marine oils that preserve their broader lipid architecture offer a more complete immuno-metabolic-regulatory profile than heavily refined isolates.
Fish oils do not contain vitamins A and D naturally. If these are present in a blend, they are synthetic additives. Cod liver oil is the only form of fish oil that contains these vitamins. Even so, many companies add synthetic A and D to bolster their numbers or because they were destroyed in processing.
And that may explain why traditional cod liver oil — rich in EPA, DHA, DPA, and fat-soluble vitamins in their natural matrix — continues to hold relevance in modern preventive health strategies.
Looking for a Smarter Approach to Omega-3 Supplementation?
Not all fish oils are created equal. If you’re prioritizing immune balance, inflammation resolution, and cardiovascular resilience, the form of omega-3 you choose matters.
Formula IQ Cod Liver Oil is minimally processed to preserve its natural spectrum of marine fatty acids, including EPA, DHA, and DPA, along with naturally occurring vitamins A and D, just as nature intended.
If you’re ready to move beyond highly processed fish oil and synthesized nutrients and are looking for a more biologically complete omega-3, explore Formula IQ Cod Liver Oil and experience the difference that quality and formulation can make.
