A sustainable source of freshwater fish oil: Nutritional and functional insights through lipidomics and metabolomics

Freshwater fish oil is a promising source of essential fatty acids, including omega-3, omega-6, and omega-9, with potential health benefits such as anti-inflammatory, anti-obesity, anti-diabetic, and cardiovascular protection. Although its omega-3 content is generally lower than that of marine fish oil, its higher omega-9 levels may offer enhanced anti-inflammatory effects. As demand for fish oil rises and concerns over marine overfishing grow, freshwater fish oil particularly when derived from processing by-products, offers a more sustainable alternative that promotes resource efficiency. However, research on freshwater fish oil remains limited. Key challenges include variability in composition due to species and habitat, limited clinical validation, lack of regulatory standards, and technical barriers in extraction and quality control. Risks such as contamination and oxidation also require attention. This review summarizes recent advances in extraction methods, lipid profiles, bioactive properties, and analytical tools including lipidomics and metabolomics. It highlights both the functional potential and the existing gaps, aiming to provide a foundation for future research and industrial application of freshwater fish oil as a sustainable lipid source for food, pharmaceutical, and nutraceutical sectors. • Novel integration of lipidomics and metabolomics in freshwater fish oil review. • Distinct omega-3/6/9 balance versus marine fish oil. • Green extraction advances and scalability challenges. • By-product use for zero-waste production. • Research gaps in regulation and clinical validation.