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Electronic letters to:
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Electronic letters published:
![[Read eLetter]](/icons/misc/sectionDOWN.gif){kind=icon}
Re: Long chain omega-3 supplementation
Long chain omega-3 supplementation
Omega-3 benefits may be dose-dependent
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Dr. Herbert H. Nehrlich Bribie Island, Australia 4507
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drhhnehrlich{at}westnet.com.au Dr. Herbert H. Nehrlich
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Should it cease to amaze me that we have been using fish oil to forestall and to treat many cardiovascular conditions for many years and that the debate continues? Or is it the uncertainty? If I could count on a dollar for every patient that was spared the indignity and expense of having a pacemaker fitted and/or having to ingest a multitude of drugs on a daily basis I would be in the mountains of Tibet taking it easy and living off the fat of the land, so to speak. Eicosapentaenoic and docosahexaenoic acids accomplish far more than so many of the modern (and expensive) drugs. Perhaps that could remind us that the supply of essential nutrients will do more than any medical intervention in ensuring man's future health. Conflict of Interest:None declared |
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Monique C Cashion The Omega-3 Centre
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mcashion{at}omega-3centre.com Monique C Cashion
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Dear Editor, We are writing in regards to the article entitled ‘Fish-oil supplementation in patients with implantable cardioverter defibrillators: a meta-analysis,’ by Jenkins, et al. We believe it is incorrect to conduct a mathematical meta-analysis on only three clinical studies of which there is significant heterogeneity in study patients and clinical outcomes. 1 The authors concluded that the meta-analysis suggests there is significant heterogeneity in response to fish-oil supplementation among patients with implantable cardioverter defibrillators. A more appropriate conclusion would have been “ Fish oil supplementation depends on an individual patients underlying type of heart disease and risk profile”. What is interesting , which the researchers did not comment on at all, is that the single study that seems to show no benefit to fish oil (Raitt et al) had more than 60% of the patients in the NYHA Class III or IV categories, which was not the case in the other two studies. In fact, if you removed this study from consideration as a result of this difference, you could come to a very different conclusion using the same methods the researchers used to arrive at their conclusion. Also, the Raitt et al study itself was not statistically significant (from a Relative Risk perspective). The authors appear to have not reviewed the total evidence, nor do they seem to have a clear understanding of Cardiology and sudden death and have not differentiated in the three studies between those with cardiomyopathy and coronary heart disease. They incorrectly state that the GISSI-P and Japanese JELIS studies were ‘in effect, studies of primary prophylaxis.’ The GISSI-P study was a secondary prevention study and fish oil significantly decreased sudden death and total mortality. The number of deaths in this study was 1017, of which 286 were sudden, not 69 total deaths in the meta-analysis in this paper.2 The JELIS trial involved nearly 5,000 patients that had had a heart attack, and therefore it was partly a secondary prevention trial with the other 14,000 patients being part of a primary prevention trial.3 The authors seem to be unaware of studies assessing acute loading with fish oil and prevention of ventricular tachycardia in the electrophysiology theatre, and also prevention of atrial fibrillation. They did not appear to be aware of the animal studies showing changes in ventricular fibrillation threshold due to changes in the cellular membrane and the myocardium. The authors incorrectly concluded that ‘commercial DHA’ may be a preferred form of getting omega-3s due to depletion of fish stocks. The authors do not have an understanding of where fish oils are sourced from and or managed, and since there wasn't any data on this aspect it should not be in the conclusion of the paper. In summary, the meta-analysis was done on only 3 trials of which there was significant heterogeneity regarding study patients and clinical outcomes. Most statisticians and clinicians would advise caution when doing mathematics in this situation due to the high chance of incorrect results. A simple description of the trials would have been more appropriate and helpful for the practicing clinician. Perhaps one of the most interesting comments in the paper was in the introduction, mentioning that only 0.5% of patients with coronary heart disease are taking fish oil. This is despite the American Heart Association’s (AHA) recommendations 5 years ago for all patients who have coronary heart disease to be taking the equivalent of 1g of combined EPA/DHA.4 We applaud the AHA program ‘Get With The Guidelines’ to improve adherence by clinicians and patients to evidence based guidelines to optimize cardiovascular outcomes. 5 Regards, Dr David Colquhoun, Wesley Medical Centre, Australia, Email: d.calquhoun@uq.edu.au; Adam Ismail, Global Organization for EPA and DHA Omega-3s (GOED), Email: adam@goedomega3.com; and Monique Cashion, Omega-3 Centre, Australia New Zealand, Email: mcashion@omega-3centre.com References: 1. Cook DJ, Sackett DL & Spitzer WO. Methodologic guidelines for systematic reviews of randomized control trials in health care from the Potsdam Consultation on Meta-Analysis. Journal of Clinical Epidemiology 1995; 48(1): 167-171. 2. Marchioli R, Barzi F, Bomba E, et al. Early protection against sudden death by n-3 polyunsaturated fatty acids after myocardial infarction: time-course analysis of the results of the Gruppo Italiano per lo Studio della Sopravvivenza nell’Infarto Miocardico (GISSI)-Prevenzione. Circulation 2002;105:1897-903. 3. Yokoyama M, Origasa H, Matsuzaki M, et al. Effects of eicosapentaenoic acid on major coronary events in hypercholesterolaemic patients (JELIS): a randomised open-label, blinded endpoint analysis. Lancet 2007;369:1090-8. 4. Kris – Etherton et al. AHA Nutrition Committee. Circulation 2002; 106:2747-57. 5. AHA. Get with the Guidelines. http://www.americanheart.org/presenter.jhtml?identifier=1165 Conflict of Interest:The Omega-3 Centre and Global Organisation for EPA and DHA (GOED) |
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Richard Nahas Seekers Centre for Integrative Medicine
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richard{at}seekerscentre.com Richard Nahas
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I was pleased to see the recent meta-analysis of three clinical trials evaluating the efficacy of omega-3 fatty acids on time to initial discharge and total mortality in patients with implantable cardioverter defibrillators. Unfortunately, the authors concluded that the outcomes were heterogeneous without discussing the heterogeneity of the intervention. The trial that administered the highest dose of omega-3 fatty acids (2.6 grams daily) was the only one that demonstrated effectiveness (28% vs 39%, p=0.057). While this did not reach statistical significance, it is certainly important information. While it may be premature to universally recommend that patients at cardiovascular risk increase their intake of omega-3 fatty, their potential benefit outweighs any potential risk. There is no real evidence to support the authors' final conclusion that 'the use of fish oils in patients with implantable cardioverter defibrillators appears to warrant caution.' Conflict of Interest:None declared |
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