Essential Fatty Acids: Omega-3, 6, 7, 9 Clinical Guide
For fifty years, the Western world waged a war against dietary fat. The result?
Essential Fatty Acids: Omega-3, 6, 7, 9 Clinical Guide
Fat Is Not the Enemy — The Wrong Fat Is
For fifty years, the Western world waged a war against dietary fat. The result? We replaced butter with margarine (trans fats), olive oil with soybean oil (omega-6 overload), and whole eggs with sugar-laden cereals. Heart disease, diabetes, and neuroinflammation exploded.
The truth is that fat is the primary structural component of every cell membrane in your body. Your brain is 60% fat by dry weight. Every hormone starts as a fat molecule. Every nerve signal depends on a fatty myelin sheath. The question was never whether to eat fat — it was which fats, in what ratios, and in what condition.
Essential fatty acids are called “essential” because you cannot synthesize them. Like essential amino acids, they must come from diet. And like so many nutrients in modern life, the balance has been catastrophically disrupted.
Omega-3 Fatty Acids: The Master Anti-Inflammatories
EPA (Eicosapentaenoic Acid): The Inflammation Fighter
EPA is the omega-3 that directly opposes inflammatory prostaglandins, leukotrienes, and thromboxanes produced from the omega-6 pathway. It competes with arachidonic acid (AA) for the COX and LOX enzymes — the same enzymes that NSAIDs block pharmaceutically. EPA does naturally what ibuprofen does chemically, without the GI damage.
Clinical dosing by condition:
- General health maintenance: 1-2g combined EPA+DHA
- Depression (Sublette 2011 meta-analysis — EPA-dominant formulas showed significantly greater antidepressant effect than DHA-dominant): 2-3g EPA-dominant (at least 60% EPA)
- Autoimmune conditions: 3-4g combined EPA+DHA
- Cardiovascular protection (REDUCE-IT trial — 4g icosapent ethyl reduced cardiovascular events by 25%): 4g EPA
- Traumatic brain injury (acute phase): 3-5g DHA-dominant
DHA (Docosahexaenoic Acid): The Brain Builder
DHA is the structural omega-3 — it comprises 40% of polyunsaturated fatty acids in the brain and 60% in the retina. It’s literally what brain cell membranes are made of. Every neuron, every synapse, every photoreceptor depends on DHA for membrane fluidity, signal transduction, and neuroprotection.
Critical windows:
- Pregnancy: 300-600mg DHA daily. The developing fetal brain accumulates DHA rapidly in the third trimester. Maternal DHA status directly correlates with infant cognitive development, visual acuity, and reduced preterm birth risk (Carlson 2013).
- Infancy and childhood: DHA continues to be critical for brain development through age 5.
- Aging: DHA depletion correlates with cognitive decline, Alzheimer’s risk (Framingham Heart Study — Schaefer 2006 — highest quartile DHA = 47% reduced dementia risk), and macular degeneration.
ALA (Alpha-Linolenic Acid): The Plant Omega-3
ALA from flaxseeds, chia seeds, hemp seeds, and walnuts is the plant omega-3. It is technically essential — the only omega-3 your body absolutely cannot make. But here’s the problem: conversion from ALA to EPA is only 5-10%, and to DHA less than 1%. The enzymes (delta-6 desaturase, elongase) are inefficient, and omega-6 intake competes for the same enzymes.
For vegans: ALA from plant foods alone is insufficient for therapeutic omega-3 status. Algal oil (derived from microalgae, the same source fish get their DHA from) provides direct DHA and some EPA. This is the essential vegan omega-3 supplement.
Forms: Not All Fish Oil Is Equal
Triglyceride (TG) form: Natural form as found in fish. Bioavailability is approximately 70% higher than ethyl ester form (Dyerberg 2010 crossover study). Most high-quality brands use re-esterified triglyceride form.
Ethyl ester (EE) form: Cheaper to produce, concentrated, but less bioavailable. Most prescription omega-3s (Lovaza, Vascepa) are ethyl esters. Take with a high-fat meal to improve absorption.
Phospholipid form: Krill oil delivers EPA/DHA bound to phospholipids, which mirrors how these fats are incorporated into cell membranes. Enhanced brain delivery (phospholipids cross the BBB more readily). Also contains astaxanthin (natural antioxidant). Dose-for-dose, krill may be more effective than standard fish oil, but capsules contain less total EPA/DHA.
Quality: The Non-Negotiable Standards
Fish oil oxidizes easily. Rancid fish oil is not just useless — it’s actively harmful, generating lipid peroxides and aldehydes that drive the very inflammation you’re trying to reduce. Taking rancid fish oil is worse than taking nothing.
Quality markers:
- IFOS (International Fish Oil Standards) certification: Independent third-party testing for purity and freshness. The gold standard.
- TOTOX value: Total oxidation. Below 26 is acceptable, below 10 is excellent.
- Peroxide value: Below 5 mEq/kg.
- Anisidine value: Below 20.
- Heavy metals: Mercury, lead, cadmium, arsenic — all below detectable limits. Molecular distillation removes these.
- PCBs and dioxins: Below EU limits.
Practical test: Cut open a capsule. If it smells aggressively fishy or tastes rancid, throw the bottle away. Fresh fish oil should have a mild oceanic smell, not a pungent one.
The Omega-3 Index: Testing That Matters
The Omega-3 Index (Harris and von Schacky 2004) measures EPA+DHA as a percentage of total red blood cell fatty acids. It reflects the previous 120 days of omega-3 intake — a true long-term biomarker.
Targets:
- Below 4%: High cardiovascular risk zone (associated with highest rates of sudden cardiac death)
- 4-8%: Moderate risk
- 8-12%: Optimal target (Japanese population averages 8-11%)
The average American Omega-3 Index is 4-5%. This is a population-wide deficiency with profound cardiovascular and neurological consequences.
Fish Oil vs Algal Oil
Fish oil: Higher EPA, well-studied, widely available, lower cost. Concerns: overfishing, heavy metal contamination (mitigated by molecular distillation), not suitable for vegans.
Algal oil: Direct source — microalgae produce DHA (and increasingly EPA in newer formulations). Sustainable, vegan, no heavy metal concerns. DHA-dominant, which is ideal for brain-focused applications. Growing body of research shows equivalent bioavailability to fish oil.
Omega-6 Fatty Acids: The Double-Edged Sword
Omega-6 linoleic acid (LA) is essential — you need some. But the modern Western diet has turned “some” into a flood. Soybean oil, corn oil, sunflower oil, safflower oil, processed foods — these have driven the omega-6:3 ratio from a historical 2-4:1 to a staggering 15-20:1.
The inflammatory cascade: Excess linoleic acid → arachidonic acid (AA) → pro-inflammatory prostaglandins (PGE2), leukotrienes (LTB4), and thromboxanes → chronic low-grade inflammation → accelerates every modern chronic disease.
The goal: Reduce omega-6 intake (eliminate industrial seed oils, reduce processed foods) while increasing omega-3. Target ratio: 2-4:1.
The GLA Exception
Not all omega-6 is inflammatory. Gamma-linolenic acid (GLA), found in evening primrose oil, borage oil, and black currant seed oil, takes a detour down the anti-inflammatory DGLA (dihomo-gamma-linolenic acid) pathway, producing PGE1 — a potent anti-inflammatory prostaglandin.
Clinical dosing: 1-3g GLA-rich oil (equivalent to 240-720mg GLA).
Applications: Eczema and atopic dermatitis (Morse 2006), PMS and breast pain, rheumatoid arthritis, diabetic neuropathy. Particularly useful when delta-6-desaturase is impaired (diabetes, aging, zinc deficiency, trans fat exposure) — these patients cannot convert LA to GLA and benefit enormously from direct supplementation.
Omega-7: The Mucosal Membrane Support
Palmitoleic acid (omega-7) is found in sea buckthorn oil and macadamia nuts. It is not “essential” in the biochemical sense, but it has emerging clinical utility for mucosal membrane health.
Applications:
- Dry eyes: Improves tear film quality and reduces inflammation (Larmo 2010 — sea buckthorn supplementation improved dry eye symptoms).
- Dry mouth (xerostomia): Supports salivary gland function.
- Vaginal dryness: Restores mucosal moisture — particularly relevant for postmenopausal women who cannot or choose not to use estrogen.
- Metabolic health: Preliminary data suggests palmitoleic acid improves insulin sensitivity and reduces hepatic fat (Bernstein 2014).
Clinical dosing: 200-400mg palmitoleic acid (requires purified sea buckthorn oil — crude forms also contain palmitic acid, which you don’t want).
Omega-9: Therapeutic but Not Essential
Oleic acid (omega-9) — the primary fat in olive oil, avocados, macadamia nuts, and almonds — is technically not essential because the body can synthesize it. But its therapeutic value makes it a cornerstone of the most evidence-based diet in medicine: the Mediterranean diet.
Oleocanthal in extra virgin olive oil is a natural COX-1 and COX-2 inhibitor — pharmacologically similar to ibuprofen. Beauchamp 2005 in Nature demonstrated that 50ml of EVOO provides anti-inflammatory activity equivalent to approximately 10% of an adult ibuprofen dose. Every day. Without side effects.
Oleic acid is also the backbone of membrane fluidity in warmer tissues, anti-inflammatory signaling, and cardiovascular protection. The PREDIMED trial (discussed in the Mediterranean diet article) demonstrated its power when consumed as part of a whole-food pattern.
SPMs: Specialized Pro-Resolving Mediators
This is the frontier of fatty acid science. For decades, we thought inflammation simply “burned out.” We now know that resolution of inflammation is an active process — orchestrated by specialized molecules derived from EPA and DHA.
The three families:
- Resolvins (from EPA → E-series resolvins; from DHA → D-series resolvins): Actively resolve inflammation by stopping neutrophil infiltration and promoting macrophage cleanup of debris.
- Protectins (from DHA → neuroprotectin D1): Protect neural tissue from inflammatory damage. Critical in neuroinflammation, TBI, and neurodegeneration.
- Maresins (from DHA, produced by macrophages): Promote tissue regeneration and wound healing.
Charles Serhan at Harvard discovered this resolution pathway, fundamentally changing our understanding of inflammation. Inflammation is not just about turning off the fire — it’s about actively cleaning up and rebuilding.
Clinical application: SPM supplementation (e.g., Metagenics SPM Active) provides pre-formed resolvins and protectins. Used for chronic inflammation that won’t resolve — autoimmune flares, post-surgical recovery, chronic pain, neuroinflammation. Dosing: 2-6 softgels daily for acute resolution, 1-2 for maintenance.
Why some people stay inflamed: If EPA/DHA intake is insufficient, the body cannot produce adequate SPMs, and inflammation fails to resolve. This is one mechanism explaining why omega-3 deficiency correlates with chronic inflammatory disease — it’s not just about reducing pro-inflammatory signals, it’s about being unable to produce pro-resolving ones.
Putting It All Together: The Fatty Acid Assessment
Testing:
- Omega-3 Index: 8-12% target (RBC EPA+DHA %)
- AA:EPA ratio: Reflects inflammatory balance. Optimal below 3:1 (most Americans are 10-20:1).
- Full fatty acid panel: Measures all fatty acid families — omega-3, 6, 7, 9, saturated, trans. Identifies specific imbalances.
The clinical protocol:
- Eliminate industrial seed oils (soybean, corn, sunflower, canola for cooking)
- Reduce processed food omega-6 exposure
- Increase fatty fish to 2-3 servings per week (wild salmon, sardines, mackerel, anchovies, herring — the SMASH fish)
- Supplement EPA+DHA by condition (1-4g)
- Cook with stable fats (avocado oil, ghee, coconut oil, EVOO for low heat)
- Add GLA if indicated (skin, hormones, autoimmune)
- Test Omega-3 Index in 3-4 months, adjust
- Consider SPMs for stubborn inflammatory conditions
Every cell membrane in your body is built from the fats you eat. Every inflammatory signal and every resolution signal derives from fatty acid precursors. When you change the fat composition of your diet, you literally change the material your cells are made of and the signals they send.
What kind of membranes are you building today?