EPA / DHA

The Two Omega-3s That Actually Do Something

There are many omega-3 fatty acids. Only two matter for your health at the level you should care about: EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid). They are classified as essential fatty acids because your body cannot synthesize them. You have to get them from food or supplementation. The problem is that most people — even those who eat fish occasionally — are chronically under-dosed on both.

ALA, the plant-based omega-3 found in flaxseed and walnuts, is often cited as an alternative. It isn’t. The human body converts less than 5% of ALA into EPA, and almost none into DHA. Chia seeds don’t count. If you want the cardiovascular and neurological benefits that decades of research have documented, you need the marine-sourced, long-chain forms — EPA and DHA directly.

EPA: The Anti-Inflammatory Engine

EPA is the workhorse when it comes to cardiovascular and metabolic protection. It competes directly with arachidonic acid — the pro-inflammatory fatty acid that dominates the modern Western diet — for the same enzymatic pathways in your cell membranes. When EPA wins that competition, the downstream signaling shifts from inflammatory to resolving. Fewer cytokines. Lower CRP. Less arterial inflammation.

The landmark REDUCE-IT trial, published in the New England Journal of Medicine, enrolled over 8,000 patients with elevated triglycerides and established cardiovascular disease or diabetes. Participants received 4,000mg of pure EPA daily. The result: a 25% reduction in major adverse cardiovascular events including heart attack, stroke, and cardiovascular death. This was not a marginal finding — it rivaled the best cholesterol drugs on the market. Notably, similar trials using DHA-containing formulations did not replicate this cardiovascular event reduction, which is why pure-EPA pharmaceutical formulations (Vascepa/icosapent ethyl) have been FDA-approved specifically for triglyceride and cardiac risk reduction.

DHA: The Structural Fat Your Brain Is Made Of

DHA is not primarily a signaling molecule — it’s structural. Approximately 97% of the omega-3 fat in the brain is DHA, and roughly 93% of the omega-3 in the retina. It is literally the material your neurons are built from. When DHA is deficient, cell membrane fluidity decreases, synaptic signaling slows, and neurodegeneration accelerates.

The evidence connecting DHA to cognitive aging is substantial. Low DHA levels in midlife are associated with significantly increased risk of Alzheimer’s disease decades later. Studies in older adults with mild cognitive impairment show DHA supplementation slows hippocampal atrophy — measurable brain shrinkage — by up to 40% compared to placebo. DHA is also the dominant fat in photoreceptor cells, and its decline is directly linked to age-related macular degeneration.

Triglycerides and Metabolic Health in Diabetics

For diabetics specifically, the combined EPA+DHA effect on triglycerides is immediately relevant. Elevated triglycerides are a defining marker of insulin resistance and track closely with cardiovascular risk in T2D. Multiple meta-analyses of randomized controlled trials confirm that EPA+DHA supplementation reduces fasting triglycerides by an average of 20–30% at doses of 2,000–4,000mg per day.

EPA and DHA also activate PPAR-alpha, a nuclear receptor that upregulates fat oxidation — meaning your body shifts toward burning fat for fuel rather than storing it. A 2025 meta-analysis of omega-3 interventions in type 2 diabetes found significant improvements in HbA1c, fasting insulin, insulin resistance (HOMA-IR), and inflammatory markers including TNF-alpha and IL-6. These are not peripheral effects — they address the core drivers of metabolic dysfunction directly.

How to Take It

Dose: For general cardiovascular and metabolic health, 2,000–3,000mg of combined EPA+DHA daily. For active triglyceride reduction or cardiovascular risk management, 3,000–4,000mg. Read the label carefully — the total fish oil capsule weight is not your EPA+DHA dose. A 1,000mg softgel may contain only 300mg of actual EPA+DHA.

Form: Triglyceride (TG) form absorbs roughly 70% better than ethyl ester (EE) form. Most cheap fish oil is ethyl ester. Look for “triglyceride form” or “re-esterified triglycerides” on the label. Krill oil contains phospholipid-bound omega-3s which absorb well, but requires significantly more capsules to reach therapeutic doses.

Timing: Take with your fattiest meal of the day. Fat in the meal triggers bile release, which dramatically improves absorption of fat-soluble compounds. Taking fish oil on an empty stomach is largely wasted — and the reason many people experience the fishy reflux that gives omega-3s a bad name.

Freshness: Omega-3s oxidize rapidly. Rancid fish oil is pro-inflammatory — the opposite of the point. Buy from brands with IFOS certification (third-party freshness testing), store in the refrigerator after opening, and discard any capsules with a strong rancid odor.

This page is for informational purposes only and is not medical advice. Consult your physician before making changes to your medications or supplement regimen.