Ascenta's response to Cardiovascular Outcomes Study - March 2014
The cardiovascular effects of omega-3 fatty acids have been receiving a lot of press in popular media these days, and they have been the subject of heated controversy. A recently published study called the Cardiovascular Outcomes Study fueled this controversy. Unfortunately, inaccuracies in this study have resulted in unfounded negative media attention regarding the heart healthy benefits of omega-3 fatty acids.
The authors of the Cardiovascular Outcomes Studyoriginally concluded that their “results are consistent with a growing body of evidence from clinical trials that have found little CVD [cardiovascular disease] benefit from moderate levels of dietary supplementation” with omega-3 fatty acids.The desire to dwell on “negative” nutrition findings led to the publication of these findings in many media outlets. What did not receive much media attention, however, was the fact that the authors issued a correction to the study (although they have not retracted the paper). The uncovering ofserious mistakes with this study changed the results from “negative” to positive. The original publication states that the impact of long-chain omega-3 fatty acids on coronary health was statistically non-significant, but the corrected article reports it as significant. More specifically, long-chain omega-3 fatty acids resulted in an important 13% reduction in coronary outcomes.
Since the initial study was published, the following corrections have been made:
· The addition of the line “Conversely, dietary long-chain omega-3 polyunsaturated fatty acids was associated with a lower risk of coronary disease.”
· The removal of the line “Nutritional guidelines on fatty acids and cardiovascular guidelines may require reappraisal to reflect the current evidence.”
Ascenta wants to highlight the fact that this study actually supports the intake of EPA and DHA for heart health benefits, something that we believe is well supported in the scientific literature. The totality of the scientific research demonstrates a heart-protective benefit of omega-3 fatty acids in both healthy populations and in populations with pre-existing heart ailments. Here are some key studies to highlight:
· The famous open-label GISSI-Prevenzione Study, which assessed 11,324 patients who had survived a heart attack, found that 1 gram daily of omega-3 fatty acids significantly lowered the risk of overall death by 14-20% and cardiovascular death by 17-30%[i]. A re-analysis of this data revealed that overall death rates were significantly lower in the omega-3 group after only 90 days of supplementation compared to placebo and sudden death rates were significantly lower after only 120 days[ii]. These results speak to the power of omega-3 fatty acids in that supplementation for only 3 to 4 months can lead to significantly reduced death rates.
· The Japan EPA Lipid Intervention Study (JELIS) assessed 19,000 Japanese adults with high cholesterol who were taking a statin medication (i.e., pravastatin or simvastatin) and found that 1.8 grams daily of EPA led to a significant 19% relative reduction in major heart-related events[iii].
· A systematic review of randomized controlled clinical trials on various lipid-lowering interventions (i.e., diet, niacin, resins, statins, and fibrates) compared the efficacy of treatment on mortality and found that omega-3 fatty acids provided the most protection against overall death and cardiovascular death by reducing risk by 23% and 32%, respectively[iv].
· A meta-analysis that included a total of 176,441 subjects from 7 prospective studies revealed that subjects consuming the highest level of marine omega-3 fatty acids had a 14% reduced risk of heart failure compared to those consuming the lowest level[v].
· Finally, a prospective cohort study involving 2,692 healthy older adults revealed thatcirculating individual and total omega-3 fatty acid levels were associated with lower overall death. Subjects with the highest blood levels of omega-3 fatty acids had 27% lower overall death risk compared to those with the lowest levels of omega-3 fatty acids; the lower risk was vastly attributable to fewer heart-related deaths than non-heart-related deaths. Additionally, the mortality differences corresponded to living an average of 2.22 more years after the age of 65 years in those with the highest versus lowest omega-3 fatty acid levels[vi].
Interestingly, the original publication actually had positive study results showing that omega-3 fatty acids help reduce the long-term risks of heart disease in certain populations; the desire to dwell on the “negative” findings overshadowed these positive results. In the original publication, omega-3 fatty acids contributed a significant heart-protective effect in people who had no previous history of high blood pressure. The authors also reported a trend toward the benefits of omega-3 fatty acid supplementation on heart disease risk in people with no history of heart disease or no elevated cholesterol levels. These results support the importance of omega-3 fatty acids in preventing heart disease among healthy populations.
[i] Dietary supplementation with n-3 polyunsaturated fatty acids and vitamin E after myocardial infarction: results of the GISSI-Prevenzione trial. Gruppo Italiano per lo Studio della Sopravvivenza nell'Infarto miocardico.Lancet, 1999. 354(9177): p. 447-55.
[ii] Marchioli, R., 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(16): p. 1897-903.
[iii] Yokoyama, 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(9567): p. 1090-8.
[iv] Studer, M., et al., Effect of different antilipidemic agents and diets on mortality: a systematic review. Arch Intern Med, 2005. 165(7): p. 725-30.
[v] Djousse, L., et al., Fish consumption, omega-3 fatty acids and risk of heart failure: A meta-analysis. Clin Nutr, 2012.
[vi] Mozaffarian, D., et al., Plasma phospholipid long-chain omega-3 fatty acids and total and cause-specific mortality in older adults: a cohort study. Ann Intern Med, 2013. 158(7): p. 515-25.