From structure to function: a review of absorption mechanisms and chronic metabolic disease interventions of phospholipid-bound omega-3 polyunsaturated fatty acids

Phospholipid-bound omega-3 polyunsaturated fatty acids (PL-ω-PUFAs) represent a novel class of functional lipids with glycerophospholipids as carriers, which have garnered extensive attention in the intervention of chronic metabolic diseases. This review systematically summarizes the natural sources, molecular structural characteristics, intestinal digestion, absorption, and metabolic transport mechanisms of PL-ω-PUFAs, consolidates research progress in their regulation of blood lipid metabolism, anti-inflammatory and antioxidant effects, cardiovascular protection, nervous system maintenance, and glucose homeostasis regulation, and analyzes their differentiated effects compared with traditional triglyceride-type omega-3 in terms of bioavailability, tissue targeting, and oxidative stability. Current evidence indicates that PL-ω-PUFAs are at least partially absorbed through the intestinal lysophosphatidylcholine carrier pathway via MFSD2A, although the quantitative contribution of this pathway relative to passive diffusion remains incompletely defined and appears to depend on dietary fat content. PL-ω-PUFAs can be selectively enriched in the brain, retina, vascular endothelium, and hepatocyte membranes, exerting multi-target regulatory effects that may ameliorate hypertriglyceridemia, insulin resistance, and metabolic syndrome. However, these conclusions are based predominantly on short-term randomized trials, selected populations, and preclinical models. Large-sample long-term follow-up data with hard endpoints, as well as the differential efficacy mechanisms of various phospholipid subtypes, remain lacking. The clinical superiority of PL-ω-3 over TG-ω-3 should therefore be regarded as suggestive rather than established.