Most of the billions spent by consumers on omega 3 are used for general health or heart-protective functions. Many studies with fish-eating populations show an inverse association with heart disease (discussed before). We have already seen that fish has many healthy attributes, which should not be confused with fish oils. Some studies show Omega 3 supplementation benefits heart patients, but other studies are less convincing.
Some examples;
- myocardial infarction or stroke”[i] (the group did use a stricter P interval value of 0.0063). In Italy, a randomized placebo-controlled clinical trial, enrolled 860 general practitioners, 12,513 patients, men and women with multiple cardiovascular risk factors or atherosclerotic vascular disease (excluding myocardial infarction) were followed for 5 years. The patients either received 1 gram of n-3 fatty acid or a placebo (olive oil). The study concluded “that there was no significant benefit of n−3 fatty acids in reducing the risk of death from cardiovascular causes or hospital admission for cardiovascular causes”.[ii]
- In the United Kingdom, an interested study that divided 3114 men in 4 groups ( groups 1, advised to eat fatty fish or take omega 3 capsules, group 2, advised to eat more vegetables and fruits, and oats; groups 3, given both types of advice; group 4, specific advice), all men were under the age of 70 with angina, showed that the group that were told to eat fatty fish or consume omega 3 capsules were worst off (especially fish oil capsules consumers) with regards to cardiac death)[iii].
- In the Netherlands, 4837 patients with a myocardial infarction history were placed in a double blind, placebo controlled trail. These patients were divided into 4 groups ( group 1 received margarine supplemented with 400 mg EPA/DHA, group 2 received margarine supplemented with 2 gram of ALA, group 3 received margarine supplemented with EPA/DHA and ALA, group 4 received a margarine placebo. The study group wrote “In this study, a low dose of EPA–DHA had no effect on the rate of major cardiovascular events in patients who had had a myocardial infarction”[iv].
- The same group used data from the study described above following 639 patienst for 40 months and again 4 groups were followed : group 1 control, group 2 ALA (2 gram), group 3 EPA-DHA (400 mg), group 4 EPA DHA and ALA (2 gram plus 400mg). The patients were measured on N-Terminal-pro Brain Natriuretic Peptide (NT-proBNP), a biomarker of heart failure. The results showed that all the fish oil groups had elevated levels compared to placebo group[v]
- In France, 2501 patients with a history of myocardial infarction, unstable angina, or ischaemic stroke were placed in a double blind, randomized, placebo controlled trail. This study both found no significant effect of supplementing omega 3 on the reduction of major vascular events, compared to the placebo[vi].
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[i] Association between omega-3 fatty acid supplementation and risk of major cardiovascular disease events: a systematic review and meta-analysis. EC Rizos, EE Ntzani, E Bika, MS Kostapanos, and MS Elisaf. Review published: 2012.
[ii]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
[iii] Lack of benefit of dietary advice to men with angina: results of a controlled trial ML Burr1 *, PAL Ashfield-Watt1 , FDJ Dunstan1 , AM Fehily2 , P Breay1 , T Ashton1 , PC Zotos1 , NAA Haboubi3 and PC Elwood1 1 University of Wales College of Medicine, Cardiff, UK; 2 Tinuviel Software, Warrington, UK; and 3 Carmarthenshire NHS Trust, Carmarthen, UK
[iv] n–3 Fatty Acids and Cardiovascular Events after Myocardial Infarction. Daan Kromhout, M.P.H., Ph.D., Erik J. Giltay, M.D., Ph.D., and Johanna M. Geleijnse, Ph.D., for the Alpha Omega Trial Group*N Engl J Med 2010; 363:2015-2026November 18, 2010DOI: 10.1056/NEJMoa1003603
[v]No effect of n-3 fatty acids supplementation on NT-proBNP after myocardial infarction: The Alpha Omega Trial
[vi]Effects of B vitamins and omega 3 fatty acids on cardiovascular diseases: a randomised placebo controlled trial BMJ 2010; 341 doi: http://dx.doi.org/10.1136/bmj.c6273 (Published 29 November 2010)Cite this as: BMJ 2010;341:c6273