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It is unsurprising fish oils did nothing for Italian adults with multiple cardiovascular risk factors. (1) Unfortunately the absorption of fish oils is impaired in diabetes and in old age (younger in those with poor lifestyles). The lack of absorption of omega 3 essential fatty acid (EFAs) may be one of the reasons why these population groups are at high risk of cardiovascular events in the first place.
Many omega 3 research trials do not consider the omega 3/6 ratio Long-chain polyunsaturated fatty acid (LCPUFA) which is vital to the eicossanoid balance. The successful absorption of essential fatty acids (EFAs) also relies on adequate levels of certain vitamins and minerals. The poor absorption of EFAs is further confounded by consuming a high carbohydrate diet such as recommended to those with type 2 diabetes. (2)
Over nutrition triggers the onset of oxidative stress in the liver due to higher availability and oxidation of fatty acids, with development of hyperinsulinemia and insulin resistance, and omega 3 LCPUFA depletion, with enhancement in the omegas 6/3 LCPUFA ratio favouring a pro-inflammatory state. (3)
Fish oil supplements are also prone to rancidity if stored incorrectly, further compromising their efficacy.
The absorption of essential fatty acids is a complex subject, in which the simplest of detail can compromise the study results. Omega 3 is fundamentally vital to good health. However it cannot be studied as a singular factor. A healthy diet relies on a synergy of many ingredients and this study confirms this fact.
(1) n–3 Fatty Acids in Patients with Multiple Cardiovascular Risk Factors The Risk and Prevention Study Collaborative Group N Engl J Med 2013; 368:1800-1808May 9, 2013DOI: 10.1056/NEJMoa1205409
(2) Re: Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. Jane E Collis. http://www.bmj.com/content/346/bmj.e8707/rr/630582
(3) Valenzuela R, Videla LA.The importance of the long-chain polyunsaturated fatty acid n-6/n-3 ratio in development of non-alcoholic fatty liver associated with obesity. Food Funct. 2011 Nov;2(11):644-8. doi: 10.1039/c1fo10133a. Epub 2011 Oct 19.
Re: No cardiovascular benefit from fish oil for high risk adults
It is unsurprising fish oils did nothing for Italian adults with multiple cardiovascular risk factors. (1) Unfortunately the absorption of fish oils is impaired in diabetes and in old age (younger in those with poor lifestyles). The lack of absorption of omega 3 essential fatty acid (EFAs) may be one of the reasons why these population groups are at high risk of cardiovascular events in the first place.
Many omega 3 research trials do not consider the omega 3/6 ratio Long-chain polyunsaturated fatty acid (LCPUFA) which is vital to the eicossanoid balance. The successful absorption of essential fatty acids (EFAs) also relies on adequate levels of certain vitamins and minerals. The poor absorption of EFAs is further confounded by consuming a high carbohydrate diet such as recommended to those with type 2 diabetes. (2)
Over nutrition triggers the onset of oxidative stress in the liver due to higher availability and oxidation of fatty acids, with development of hyperinsulinemia and insulin resistance, and omega 3 LCPUFA depletion, with enhancement in the omegas 6/3 LCPUFA ratio favouring a pro-inflammatory state. (3)
Fish oil supplements are also prone to rancidity if stored incorrectly, further compromising their efficacy.
The absorption of essential fatty acids is a complex subject, in which the simplest of detail can compromise the study results. Omega 3 is fundamentally vital to good health. However it cannot be studied as a singular factor. A healthy diet relies on a synergy of many ingredients and this study confirms this fact.
(1) n–3 Fatty Acids in Patients with Multiple Cardiovascular Risk Factors The Risk and Prevention Study Collaborative Group N Engl J Med 2013; 368:1800-1808May 9, 2013DOI: 10.1056/NEJMoa1205409
(2) Re: Use of dietary linoleic acid for secondary prevention of coronary heart disease and death: evaluation of recovered data from the Sydney Diet Heart Study and updated meta-analysis. Jane E Collis.
http://www.bmj.com/content/346/bmj.e8707/rr/630582
(3) Valenzuela R, Videla LA.The importance of the long-chain polyunsaturated fatty acid n-6/n-3 ratio in development of non-alcoholic fatty liver associated with obesity. Food Funct. 2011 Nov;2(11):644-8. doi: 10.1039/c1fo10133a. Epub 2011 Oct 19.
Competing interests: No competing interests