LCPUFA

LCPUFA stands for long-chain polyunsaturated fatty acids, a group of fatty acids with multiple double bonds and typically 20 or more carbon atoms. Common LCPUFAs include arachidonic acid (AA, 20:4, n−6), eicosapentaenoic acid (EPA, 20:5, n−3) and docosahexaenoic acid (DHA, 22:6, n−3). They are distinct from shorter essential 18-carbon polyunsaturated fatty acids such as linoleic acid (LA) and alpha-linolenic acid (ALA), which can be metabolically elongated and desaturated to form some LCPUFAs in humans, though conversion rates are limited.

Physiological roles of LCPUFAs include structural components of cell membranes, modulation of membrane fluidity, precursors for bioactive lipid mediators (eicosanoids and docosanoids), and critical functions in neural and retinal development. DHA is especially concentrated in brain and retinal tissue and is linked to cognitive and visual development in infancy. EPA and DHA are studied for effects on inflammation, lipid profiles and cardiovascular risk.

Dietary sources of LCPUFAs include oily fish, fish oils, algal oils (vegetarian source of DHA), and enriched foods; AA is present in meat and eggs. Clinical and public health guidance often addresses intake during pregnancy, infancy and for cardiovascular health. Biomarkers such as erythrocyte membrane EPA+DHA (Omega-3 Index) are used to assess status.

Safety and efficacy depend on dose, balance between n−6 and n−3 families, and individual context. High-dose supplementation can have side effects and interactions; contaminant content in some marine sources is an additional consideration.