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Omega-3 fatty acids: cardiovascular benefits, sources and sustainability

Abstract

The evidence for the cardioprotective nature of omega-3 fatty acids is abundant, and currently available data indicate that patients with known coronary heart disease should consume at least 1 g daily of long-chain omega-3 fatty acids from either oily fish or fish-oil supplements, and that individuals without disease should consume at least 250–500 mg daily. However, this area of research poses two questions. Firstly, which is the best source of omega-3 fatty acids—fish or fish-oil supplements? Secondly, are recommendations for omega-3 supplementation warranted in view of the rapid depletion of world fish stocks? The argument that eating fish is better than taking fish-oil supplements stems from the fact that several important nutrients, such as vitamin D, selenium, and antioxidants, are missing from the supplements. However, three major prevention trials have clearly indicated that omega-3 fatty acid capsules confer cardiovascular benefits and, therefore, that both are cardioprotective. Sustainable sources of omega-3 fatty acids will need to be identified if long-term cardiovascular risk reduction is to be achieved at the population level.

Key Points

  • Patients with coronary heart disease should consume at least 1 g daily of long-chain omega-3 fatty acids from oily fish or fish-oil supplements

  • Individuals without heart disease should consume 250–500 mg daily of long-chain omega-3 fatty acids from oily fish or fish-oil supplements

  • Fish-oil supplements and fish are equally good sources of omega-3 fatty acids

  • Both docosahexaenoic acid and eicosapentaenoic acid are cardioprotective and should be taken together

  • Wild fish stocks are declining, but other viable sources of omega-3 fatty acids are being investigated

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Figure 1: Schematic of potential dose–response curves that indicate the beneficial physiological effects for intake of long-chain omega-3 fatty acids.

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Acknowledgements

Lori Wilson, research assistant to Dr. O'Keefe, helped coordinate manuscript construction (references) and display items, as well as to obtain permissions. She also assisted in coordinating all the coauthors' efforts.

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Correspondence to James H. O'Keefe.

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J. H. Lee has no conflicts of interest to disclose.

J. H. O'Keefe has received research grants from and is a consultant for Cardiotabs LLC and GlaxoSmithKline. Consultancy work for Cardiotabs LLC was unpaid.

C. J. Lavie has been a speaker and consultant for Reliant Pharmaceuticals.

W. S. Harris is a consultant for, and has received research grants from, GSK and the Monsanto Company. He has also been a speaker for GSK and is a stockholder for OmegaQuant.

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Lee, J., O'Keefe, J., Lavie, C. et al. Omega-3 fatty acids: cardiovascular benefits, sources and sustainability. Nat Rev Cardiol 6, 753–758 (2009). https://doi.org/10.1038/nrcardio.2009.188

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