EDITORIAL URRENT C OPINION
From where will all the omega-3 fatty acids come? Richard J. Deckelbaum a and Philip C. Calder b,c
There is a substantial and increasing body of evidence that higher intakes of omega-3 (n-3) long chain polyunsaturated fatty acids (LC-PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are beneficial in a number of health areas. These include improved pregnancy outcomes, better growth and development outcomes for children, mental health, inflammatory diseases, immunological disorders and, although somewhat controversial, cardiovascular disease [1,2]. Because of these health benefits, organizations have recommended intakes of between 250 and 1000 mg/day of EPA and DHA, as summarized in the article of Salem and Eggersdorfer (pp. 147–154) in this issue. Despite these recommendations, intakes of n-3 LC-PUFA in most world populations are low in terms of absolute amounts of EPA and DHA [3–7], as well as diets having lower n-3/n-6 ratios than are considered appropriate [8]. Thus, current recommendations are not being met by most people. The richest natural source of n-3 LC-PUFA is seafood. However, many marine sources are under threat [9]. If the recommendations for n-3 LC-PUFA intake are to be followed, where will all the n-3s come from? The study of Salem and Eggersdorfer (pp. 147– 154) summarizes the dilemma. Current supplies of n-3 LC-PUFA that can be obtained from wild fish or fish raised in aquaculture are inadequate to meet present demand, and going forward will likely not provide the needed supplies worldwide. As discussed by these authors, as well as by many others, the essential fatty acid for the n-3 series, alpha-linolenic acid (ALA), has very inefficient conversion to bioactive EPA and DHA, focusing on the need to provide preformed EPA and DHA to gain maximal health benefit from n-3 fatty acids. Their study describes potential alternative sources for obtaining the bioactive n-3 LC-PUFA. While selective species of algae can produce oils rich in DHA as well as EPA, at present, this can only meet a small part of the n-3 LC-PUFA supply deficit, and with current methods of production, it is likely that algal sources will continue to be expensive. The authors also indicate that krill oil does not seem to be a major alternative source to vastly increase production and is also still more costly than fish oil as a source of n-3 LC-PUFA.
Still, krill oil may help decrease the n-3 LC-PUFA supply deficit. Are there other alternative sources of n-3 fatty acids to consider? The answer is yes. Genetically modified soybeans have been produced which have high levels of stearidonic acid (SDA) [10]. SDA is converted to EPA with greater efficiency than ALA, and feeding soybean oil rich in SDA has been reported in clinical trials to increase EPA in blood plasma and red and white cell membranes in humans [11]. Also, Kennedy et al. [12] reported that SDA-enriched soybean oil could be an inexpensive approach towards increasing n-3 fatty acid intakes in humans even when compared to fish sources. Genetically modified plants are also becoming available as sources of EPA and DHA [13]. However, scientific and political arguments as well as initial production costs are likely to remain as barriers to using genetically modified plants, at least in the near future. Another interesting approach to inexpensively increase n-3 fatty acid supply is being funded by the Bill and Melinda Gates Foundation with the approach of using single-cell photosynthetic organisms and making them convert sunlight, CO2 and salt water directly into n-3 fatty acids (http://archive.today/vdHl). It has been traditionally accepted that cold water fish are the major sources for rich supplies of EPA and DHA. However, there are recent provocative suggestions that warm water fish from certain regions might also be rich sources of n-3 LC-PUFA. Fish wastes from Nile perch from Lake Victoria in Eastern Africa have been shown to be particularly high in oil rich in DHA and EPA [14]. As well, a Institute of Human Nutrition and the Department of Pediatrics, Columbia University Medical Center, New York, USA, bHuman Development and Health Academic Unit, Faculty of Medicine, University of Southampton and cNIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
Correspondence to Richard J. Deckelbaum, MD, CM, FRCP(C), Institute of Human Nutrition, Columbia University Medical Center, 630W 168th Street, PH 15E, Suite 1512, New York, NY 10032, USA. Tel: +1 212 305 4808; fax: +1 212 305 3079; e-mail: [email protected] Curr Opin Clin Nutr Metab Care 2015, 18:111–112 DOI:10.1097/MCO.0000000000000153
1363-1950 Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.co-clinicalnutrition.com
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Lipid metabolism and therapy
another study has recently indicated that Nile tilapia are also rich in DHA and EPA [15]. However, since tilapia have relatively low contents of oil in terms of total body composition, it seems that most of the n-3 LC-PUFA is derived from phospholipid membranes in these fish. A possible explanation for high levels of n-3 LC-PUFA in these warm water fish has been suggested to be associated with high intakes of n-3 fatty acid rich algae and weed plants in warm water lakes and rivers in temperate regions [14]. Looking ahead, we need to consider some of these unconventional, economically viable sources for n-3 fatty acids; these would include better use of fish wastes and warm water fish available in temperate regions. Thus, with the increasing recognition that individuals and populations in most countries have lower intakes of n-3 LC-PUFA than recommended by organizations and advisory panels providing guidance on such intakes, resolution of the n-3 supply deficit is needed now. While fish have traditionally been regarded as the major source for n-3 LC-PUFA, it seems clear that even with expanding aquaculture yields, other n-3 fatty acid sources will need to be utilized. These will need to be ‘safe’ in terms of economic and environmental impacts, as well as free from adverse toxic contaminants. With the high interest in novel approaches to increasing the n-3 LC-PUFA supply, we can be cautiously optimistic that solutions will be found for our ‘fishy’ dilemma. Acknowledgements None. Financial support and sponsorship None. Conflicts of interest R.J.D. has received honoraria from Glaxo Smith Kline Co., and Beijing Sciecure Pharma Ltd. He receives grant support from the National Institutes of Health, USA.
112
www.co-clinicalnutrition.com
P.C.C. has received honoraria from Pronova BioPharma, Aker Biomarine, Sancilio, DSM, Smartfish, Danone/ Nutricia, Fresenius Kabi, and B. Braun. P.C.C. serves on the Scientific Advisory Boards of Pronova BioPharma, Aker Biomarine, DSM, Smartsfish, Solutex, Sancilio and the Danone Research Centre for Specialised Nutrition; acts as a consultant to Mead Johnson Nutritionals, Vifor Pharma, Amarin Corporation and Enzymotec; and has recently received speaking honoraria from Pronova BioPharma, Smartfish, DSM, Fresenius Kabi, B. Braun and Vifor Pharma.
REFERENCES 1. Calder PC. Very long chain omega-3 (n-3) fatty acids and human health. Eur J Lipid Sci Technol 2014; 116:1280–1300. 2. Deckelbaum RJ, Calder PC. Different outcomes for omega-3 heart trials: why? Curr Opin Clin Nutr Metab Care 2012; 15:97–98. 3. Meyer BJ, Mann NJ, Lewis JL, et al. Dietary intakes and food sources of omega-6 and omega-3 polyunsaturated fatty acids. Lipids 2003; 8:391– 398. 4. Scientific Advisory Committee on Nutrition/Committee on Toxicity. Advice on fish consumption: benefits and risks. London: TSO; 2004. 5. EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA). Scientific opinion on Dietary Reference Values for fats, including saturated fatty acids, polyunsaturated fatty acids, monounsaturated fatty acids, trans fatty acids, and cholesterol. EFSA J 2010; 8:1461. 6. Rahmawaty S, Charlton K, Lyons-Wall P, Meyer BJ. Dietary intake and food sources of EPA, DPA and DHA in Australian children. Lipids 2013; 48:869– 877. 7. Papanikolaou Y, Brooks J, Reider C, Fulgoni VL 3rd. U.S. adults are not meeting recommended levels for fish and omega-3 fatty acid intake: results of an analysis using observational data from NHANES 2003–2008. Nutr J 2014; 13:31. 8. Blasbalg TL, Hibbeln JR, Ramsden CE, et al. Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century. Am J Clin Nutr 2011; 93:950–962. 9. Raatz SK, Silverstein JT, Jahns L, Picklo MJ. Issues of fish consumption for cardiovascular disease risk reduction. Nutrients 2013; 5:1081–1097. 10. Deckelbaum RJ, Calder PC, Harris WS, et al. Conclusions and recommendations from the symposium, Heart Healthy Omega-3s for Food: stearidonic acid (SDA) as a sustainable choice. J Nutr 2012; 142:641S–643S. 11. Walker CG, Jebb SA, Calder PC. Stearidonic acid as a supplemental source of v-3 polyunsaturated fatty acids to enhance status for improved human health. Nutrition 2013; 29:363–369. 12. Kennedy ET, Luo H, Ausman LM. Cost implications of alternative sources of (n-3) fatty acid consumption in the United States. J Nutr 2012; 142:605S– 609S. 13. Haslam RP, Ruiz-Lopez N, Eastmond P, et al. The modification of plant oil composition via metabolic engineering–better nutrition by design. Plant Biotechnol J 2013; 11:157–168. 14. Dunbar BS, Bosire RV, Deckelbaum RJ. Omega 3 and omega 6 fatty acids in human and animal health: an African perspective. Mol Cell Endocrinol 2014; 398:69–77. 15. Suloma A, Orgata HY, Garibay ES, et al. (2008). Fatty acid composition of Nile tilapia oreochromis niloticus muscles: a comparative study with commercially important tropical freshwater fish in Philippines. In: 8th International Symposium on Tilapia in Aquaculture, Cairo, Egypt. pp. 921–932.
Volume 18 Number 2 March 2015
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
From where will all the omega-3 fatty acids come? Richard J. Deckelbaum a and Philip C. Calder b,c
There is a substantial and increasing body of evidence that higher intakes of omega-3 (n-3) long chain polyunsaturated fatty acids (LC-PUFA), especially eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), are beneficial in a number of health areas. These include improved pregnancy outcomes, better growth and development outcomes for children, mental health, inflammatory diseases, immunological disorders and, although somewhat controversial, cardiovascular disease [1,2]. Because of these health benefits, organizations have recommended intakes of between 250 and 1000 mg/day of EPA and DHA, as summarized in the article of Salem and Eggersdorfer (pp. 147–154) in this issue. Despite these recommendations, intakes of n-3 LC-PUFA in most world populations are low in terms of absolute amounts of EPA and DHA [3–7], as well as diets having lower n-3/n-6 ratios than are considered appropriate [8]. Thus, current recommendations are not being met by most people. The richest natural source of n-3 LC-PUFA is seafood. However, many marine sources are under threat [9]. If the recommendations for n-3 LC-PUFA intake are to be followed, where will all the n-3s come from? The study of Salem and Eggersdorfer (pp. 147– 154) summarizes the dilemma. Current supplies of n-3 LC-PUFA that can be obtained from wild fish or fish raised in aquaculture are inadequate to meet present demand, and going forward will likely not provide the needed supplies worldwide. As discussed by these authors, as well as by many others, the essential fatty acid for the n-3 series, alpha-linolenic acid (ALA), has very inefficient conversion to bioactive EPA and DHA, focusing on the need to provide preformed EPA and DHA to gain maximal health benefit from n-3 fatty acids. Their study describes potential alternative sources for obtaining the bioactive n-3 LC-PUFA. While selective species of algae can produce oils rich in DHA as well as EPA, at present, this can only meet a small part of the n-3 LC-PUFA supply deficit, and with current methods of production, it is likely that algal sources will continue to be expensive. The authors also indicate that krill oil does not seem to be a major alternative source to vastly increase production and is also still more costly than fish oil as a source of n-3 LC-PUFA.
Still, krill oil may help decrease the n-3 LC-PUFA supply deficit. Are there other alternative sources of n-3 fatty acids to consider? The answer is yes. Genetically modified soybeans have been produced which have high levels of stearidonic acid (SDA) [10]. SDA is converted to EPA with greater efficiency than ALA, and feeding soybean oil rich in SDA has been reported in clinical trials to increase EPA in blood plasma and red and white cell membranes in humans [11]. Also, Kennedy et al. [12] reported that SDA-enriched soybean oil could be an inexpensive approach towards increasing n-3 fatty acid intakes in humans even when compared to fish sources. Genetically modified plants are also becoming available as sources of EPA and DHA [13]. However, scientific and political arguments as well as initial production costs are likely to remain as barriers to using genetically modified plants, at least in the near future. Another interesting approach to inexpensively increase n-3 fatty acid supply is being funded by the Bill and Melinda Gates Foundation with the approach of using single-cell photosynthetic organisms and making them convert sunlight, CO2 and salt water directly into n-3 fatty acids (http://archive.today/vdHl). It has been traditionally accepted that cold water fish are the major sources for rich supplies of EPA and DHA. However, there are recent provocative suggestions that warm water fish from certain regions might also be rich sources of n-3 LC-PUFA. Fish wastes from Nile perch from Lake Victoria in Eastern Africa have been shown to be particularly high in oil rich in DHA and EPA [14]. As well, a Institute of Human Nutrition and the Department of Pediatrics, Columbia University Medical Center, New York, USA, bHuman Development and Health Academic Unit, Faculty of Medicine, University of Southampton and cNIHR Southampton Biomedical Research Centre, University Hospital Southampton NHS Foundation Trust and University of Southampton, Southampton, UK
Correspondence to Richard J. Deckelbaum, MD, CM, FRCP(C), Institute of Human Nutrition, Columbia University Medical Center, 630W 168th Street, PH 15E, Suite 1512, New York, NY 10032, USA. Tel: +1 212 305 4808; fax: +1 212 305 3079; e-mail: [email protected] Curr Opin Clin Nutr Metab Care 2015, 18:111–112 DOI:10.1097/MCO.0000000000000153
1363-1950 Copyright ß 2015 Wolters Kluwer Health, Inc. All rights reserved.
www.co-clinicalnutrition.com
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
Lipid metabolism and therapy
another study has recently indicated that Nile tilapia are also rich in DHA and EPA [15]. However, since tilapia have relatively low contents of oil in terms of total body composition, it seems that most of the n-3 LC-PUFA is derived from phospholipid membranes in these fish. A possible explanation for high levels of n-3 LC-PUFA in these warm water fish has been suggested to be associated with high intakes of n-3 fatty acid rich algae and weed plants in warm water lakes and rivers in temperate regions [14]. Looking ahead, we need to consider some of these unconventional, economically viable sources for n-3 fatty acids; these would include better use of fish wastes and warm water fish available in temperate regions. Thus, with the increasing recognition that individuals and populations in most countries have lower intakes of n-3 LC-PUFA than recommended by organizations and advisory panels providing guidance on such intakes, resolution of the n-3 supply deficit is needed now. While fish have traditionally been regarded as the major source for n-3 LC-PUFA, it seems clear that even with expanding aquaculture yields, other n-3 fatty acid sources will need to be utilized. These will need to be ‘safe’ in terms of economic and environmental impacts, as well as free from adverse toxic contaminants. With the high interest in novel approaches to increasing the n-3 LC-PUFA supply, we can be cautiously optimistic that solutions will be found for our ‘fishy’ dilemma. Acknowledgements None. Financial support and sponsorship None. Conflicts of interest R.J.D. has received honoraria from Glaxo Smith Kline Co., and Beijing Sciecure Pharma Ltd. He receives grant support from the National Institutes of Health, USA.
112
www.co-clinicalnutrition.com
P.C.C. has received honoraria from Pronova BioPharma, Aker Biomarine, Sancilio, DSM, Smartfish, Danone/ Nutricia, Fresenius Kabi, and B. Braun. P.C.C. serves on the Scientific Advisory Boards of Pronova BioPharma, Aker Biomarine, DSM, Smartsfish, Solutex, Sancilio and the Danone Research Centre for Specialised Nutrition; acts as a consultant to Mead Johnson Nutritionals, Vifor Pharma, Amarin Corporation and Enzymotec; and has recently received speaking honoraria from Pronova BioPharma, Smartfish, DSM, Fresenius Kabi, B. Braun and Vifor Pharma.
REFERENCES 1. Calder PC. Very long chain omega-3 (n-3) fatty acids and human health. Eur J Lipid Sci Technol 2014; 116:1280–1300. 2. Deckelbaum RJ, Calder PC. Different outcomes for omega-3 heart trials: why? Curr Opin Clin Nutr Metab Care 2012; 15:97–98. 3. Meyer BJ, Mann NJ, Lewis JL, et al. Dietary intakes and food sources of omega-6 and omega-3 polyunsaturated fatty acids. Lipids 2003; 8:391– 398. 4. Scientific Advisory Committee on Nutrition/Committee on Toxicity. Advice on fish consumption: benefits and risks. London: TSO; 2004. 5. EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA). Scientific opinion on Dietary Reference Values for fats, including saturated fatty acids, polyunsaturated fatty acids, monounsaturated fatty acids, trans fatty acids, and cholesterol. EFSA J 2010; 8:1461. 6. Rahmawaty S, Charlton K, Lyons-Wall P, Meyer BJ. Dietary intake and food sources of EPA, DPA and DHA in Australian children. Lipids 2013; 48:869– 877. 7. Papanikolaou Y, Brooks J, Reider C, Fulgoni VL 3rd. U.S. adults are not meeting recommended levels for fish and omega-3 fatty acid intake: results of an analysis using observational data from NHANES 2003–2008. Nutr J 2014; 13:31. 8. Blasbalg TL, Hibbeln JR, Ramsden CE, et al. Changes in consumption of omega-3 and omega-6 fatty acids in the United States during the 20th century. Am J Clin Nutr 2011; 93:950–962. 9. Raatz SK, Silverstein JT, Jahns L, Picklo MJ. Issues of fish consumption for cardiovascular disease risk reduction. Nutrients 2013; 5:1081–1097. 10. Deckelbaum RJ, Calder PC, Harris WS, et al. Conclusions and recommendations from the symposium, Heart Healthy Omega-3s for Food: stearidonic acid (SDA) as a sustainable choice. J Nutr 2012; 142:641S–643S. 11. Walker CG, Jebb SA, Calder PC. Stearidonic acid as a supplemental source of v-3 polyunsaturated fatty acids to enhance status for improved human health. Nutrition 2013; 29:363–369. 12. Kennedy ET, Luo H, Ausman LM. Cost implications of alternative sources of (n-3) fatty acid consumption in the United States. J Nutr 2012; 142:605S– 609S. 13. Haslam RP, Ruiz-Lopez N, Eastmond P, et al. The modification of plant oil composition via metabolic engineering–better nutrition by design. Plant Biotechnol J 2013; 11:157–168. 14. Dunbar BS, Bosire RV, Deckelbaum RJ. Omega 3 and omega 6 fatty acids in human and animal health: an African perspective. Mol Cell Endocrinol 2014; 398:69–77. 15. Suloma A, Orgata HY, Garibay ES, et al. (2008). Fatty acid composition of Nile tilapia oreochromis niloticus muscles: a comparative study with commercially important tropical freshwater fish in Philippines. In: 8th International Symposium on Tilapia in Aquaculture, Cairo, Egypt. pp. 921–932.
Volume 18 Number 2 March 2015
Copyright © 2015 Wolters Kluwer Health, Inc. All rights reserved.
