Omega-3 fatty acids from fish and plants: same family different biological activity

Low intakes of the very long-chain n-3 fatty acids eicosapentaenoic acid and docosahexaenoic acid are<br/>common in most individuals living in Western countries. Seafood, especially oily fish, is a natural source<br/>of these fatty acids, which are also found in fish oil capsules. Very long-chain n-3 fatty acids are readily<br/>incorporated into transport, functional and storage pools. This incorporation is dose-dependent and<br/>follows a kinetic pattern that is characteristic for each pool. Once they are incorporated at sufficiently<br/>high levels, eicosapentaenoic acid and docosahexaenoic acid influence the physical nature of cell<br/>membranes and membrane protein-mediated responses, lipid mediator generation, cell signalling, and<br/>gene expression in many different cell types. By acting through these mechanisms, eicosapentaenoic<br/>acid and docosahexaenoic acid influence cell and tissue physiology and the way cells and tissues<br/>respond to external signals. This appears to result in improvements in disease biomarker profiles or<br/>in health-related outcomes. Because of the recognized health improvements brought about by very<br/>long-chain n-3 fatty acids, it has been recommended to increase their intake. There is also a plant n-3<br/>fatty acid, ?-linolenic acid. This can be converted to eicosapentaenoic acid, whereas conversion to<br/>docosahexaenoic acid appears to be poor in humans. The effects of ?-linolenic acid on human health<br/>appear to be due to its conversion to eicosapentaenoic acid. Since this is limited in humans, there may<br/>be little health benefit from moderately increased consumption of ?-linolenic acid as compared with<br/>increased intake of preformed eicosapentaenoic and docosahexaenoic acids.