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LETTERS: Jehangir N Din, David E Newby, and Andrew D Flapan Omega 3 fatty acids and cardiovascular disease: Authors' reply BMJ 2004; 328: 406-d-407-d [Full text]

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Fish oil is not as "clean" as algal oil

Feng Chen   (27 March 2004)

Fish oil is not as "clean" as algal oil 27 March 2004
Feng Chen, Associate Professor Department of Botany, The University of Hong Kong, Pokfulam Road, Hong Kong Send response to journal: Re: Fish oil is not as "clean" as algal oil	Editor - In the articles of Din et al (1,2), the contaminants (e.g., heavy metals, persistant organic pollutants, etc.) associated with fish oils were not addressed. Although farmed fish may contain as much omega-3 polyunsaturated fatty acids as wild fish, like wild fish the omega-3 polyunsaturated fatty acids in farmed fish rely largely on the fatty acid composition of their feed which is usually fishmeal from marine sources (3). Consequently neither farmed fish nor wild fish could eliminate the contamination problem resulting from increasingly polluted marine environment. The adverse effect of the presence of mercury in fish oils on cardioprotection has been reported(4). Marine microalgae are a more "clean" source of omega-3 polyunsaturated fatty acids. Marine microalgae are primary producers of omega-3 fatty acids. Recent studies (5) have indicated that certain species of microalgae can be cultivated in the dark using conventional industrial fermenters in which the nutrient medium composition and environmental conditions can be perfectly controlled to produce contaminants-free "fish" oils. Feng Chen References (1) Din JN, Newby DE, Flapan AD. Omega 3 fatty acids and cardiovascular disease-fishing for a natural treatment. BMJ 2003; 328: 30- 5. (2) Din JN, Newby DE, Flapan AD. Omega 3 fatty acids and cardiovascular disease. BMJ 2004; 328: 406-7. (3) Cahu C, Salen P, de Lorgeril M. Farmed and wild fish in the prevention of cardiovascular diseases: Assessing possible differences in lipid nutritional values. Nutrition metabolism and cardiovascular diseases 2004; 14: 34-41. (4) Guallar E, Sanz-Gallardo MI, van't Veer P, Bode P, Aro A, Gomez- Aracena J, Kark JD, Riemersma RA, Martin-Moreno JM, Kok FJ. Mercury, fish oils, and the risk of myocardial infarction. New England Journal of Medicine 2002, 347: 1747-54. (5) Wen ZY, Chen F. Heterotrophic production of eicosapentaenoic acid by microalgae. Biotechnology Advances 2003, 21: 273-94. Competing interests: None declared