A specific fatty acid phenotype defined by omega-3 depletion and elevated omega-6/omega-3 ratio predicted structurally unstable arterial plaques and major cardiovascular events (MACE) even when LDL-cholesterol and triglycerides were lower than in comparator patients. In a 201-person clinical discovery cohort, omega-3-depleted individuals (Phenotype B) had significantly thinner fibrous caps on optical coherence tomography (68.0 vs 94.2 μm) and nearly 2.5 times the rate of thin-cap fibroatheroma — the lesion most prone to rupture. In the UK Biobank (n = 263,481), this phenotype carried a 12–16% higher MACE hazard, most pronounced in adults over 60, with 72% of excess risk mediated through glycemic, inflammatory, and adiposity pathways.
The finding lands squarely in a long-running debate: why do statin-treated patients with well-controlled LDL still suffer heart attacks? This study adds mechanistic texture to that question by showing that lipid *composition* — not just quantity — shapes plaque biology. The omega-6/omega-3 imbalance, common in Western diets heavy in seed oils and light in fatty fish, may sustain a pro-inflammatory milieu that destabilizes plaques regardless of cholesterol levels. For adults over 60, this suggests dietary omega-3 status deserves clinical attention alongside ApoB and LDL. Important limitations: the design is observational, fatty acid phenotypes were derived unsupervised and may not transfer across labs, and the OCT cohort was small. Whether omega-3 supplementation corrects this phenotype and reduces events — as REDUCE-IT and STRENGTH debated — remains unresolved. Confirmatory randomized data are essential.