Are Omega-3 Supplements Heart-Healthy?: Page 3 of 3

Nov 14, 2016

Differences in study populations certainly may play a role. Factors—including genetics, ethnicity, and background dietary intake of omega-3 fatty acids—all may have an impact on findings. In comparing the results of long-term clinical trials of omega-3s in western countries (which have often had neutral findings) to results from Japanese trials (which generally have positive findings), Akira Sekikawa of the University of Pittsburgh (Pittsburgh, PA) postulated that the doses used in the studies played a significant part and, importantly, that higher doses may be needed to ensure the greatest cardio-protective benefits. For example, the author, pointed out, dosages administered in the Japanese trials were generally higher than those in the western trials. In a recent trial in Japan showing a cardiovascular risk reduction of 19% with omega-3 fatty acid supplementation, the dose of omega-3 fatty acids given in the study was 1800 mg/day—this is in addition to the relatively high omega-3 dietary intake in the Japanese population of greater than 1,000 mg/day.17 By comparison, in western studies, the dose range was generally 300-900 mg of omega-3s per day, and the intake of omega-3s in western populations is generally less than 300 mg/day.

In recent intervention studies that have had neutral findings, another reason there may have been unfavorable results may be due to bioavailability issues associated with when the omega-3 supplements were administered. In a commentary on the discrepancies between recent intervention trials looking at cardiovascular risk reduction versus positive findings from epidemiologic studies, Clemens von Schacky from Ludwig-Maximilians-University (Munich, Germany) suggested that many of the intervention trials advised participants to consume their supplements with breakfast, which is often a low-fat meal.18 This could have significant impacts on omega-3 bioavailability because omega-3 absorption is dependent on the fat contained in foods and could partially explain the neutral findings. He advocated for new intervention trials to assess the real effect of omega-3s, keeping in mind the issue of bioavailability as well as controlling for the background dietary intake of study populations.

Jason Wu and Dariush Mozaffarian of the Harvard School of Public Health (Boston, MA) further speculated that another likely reason for neutral findings in recent studies versus older, positive trials may be the aggressive use of antihypertensive, lipid-lowering, and antiplatelet medications in later trials.19 Since many of the risk factors addressed overlap between the effects of these medications and the effects of omega-3 fatty acids (reduction of blood pressure, blood lipids, and circulation benefits), any additional effects of omega-3 fatty acids could have been masked by drug therapy. Researchers in the field should take these and other factors into account as they design further intervention trials assessing the benefits of omega-3s for cardiovascular health.


Plenty of Promise
In spite of the mixed findings of some recent trials, omega-3 fatty acids clearly play a role in cardiovascular wellness due to their mechanism of action on cardiovascular health parameters. Epidemiological studies consistently have shown positive associations with omega-3 supplementation, and clinical trial evidence from studies conducted around the world speaks to the impressive effects of omega-3 fatty acids on heart and vascular health.

Additional research will continue to provide specific evidence to assess the magnitude of omega-3’s true benefits. In the meantime, as supplement users consider the low risk associated with omega-3 supplementation and the potential upside of promoting heart health, increasing dietary and supplemental intake should make sense. These important nutrients remain a prudent choice for improving health and well-being.  

Also read:

2016 Omega-3 Market Update: Fish Oil, Krill Oil, Astaxanthin, and More

2016 Omega-3 Science Update

“Mixed Results” of Omega-3s for Cardiovascular Health in New Government Report

Adults Should Consume 500 mg EPA and DHA Omega-3s Daily, GOED Says



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