Omega-3s protect against the risk of heart problems. New data emerges from famous research

Just days after its publication, the meta-analysis study on the role of saturated fatty acids and Omega-3s toward cardiovascular disease has been corrected in some passages. In particular, the authors admitted that Omega-3s protect against coronary heart disease, contrary to what was previously written.

A research study, the one published last March 17 in the Annals of Internal Medicine, that had immediately drawn criticism from nutritionists and scientists, who pointed out its shortcomings in methodology and final review. The study also had a major media spin. By stating that saturated fats are not very harmful to the heart and that polyunsaturated fats do not reduce cardiovascular risk, it completely contradicted the principles of healthy eating that have been suggested for years.

At what points was the study corrected?

Although many researchers asked the authors to withdraw the article because of the inadequacy of the analysis, it has undergone only modifications. One of the most substantial concerns the action of Omega-3s. In the first publication, the association between their consumption and reduced coronary risk was found to be statistically insignificant, probably due to errors in data entry from a Danish study. Instead, the corrected version reported the protective effect of EPA (eicosapentaenoic acid) and DHA (docosahexaenoic acid) on the heart, substantially changing the final message. In the corrected publication appeared, as if to support the new result, a link to a 2013 article by one of the study's co-authors showing a 27 percent reduction in mortality in elderly and adults with high blood levels of Omega-3. Regarding the relationship between fatty acids and sudden cardiac death, new inclusion criteria were established that increased the number of participants considered from 103,052 to 105,085 and the number of coronary attacks from 5,726 to 6,229.

Omega-3s protect against coronary risk

In the conclusion of the original article, the authors stated that they did not support the guidelines promoting consumption of polyunsaturated fatty acids and reduction of saturated fatty acids, in relation to cardiovascular health. The new, slightly modified conclusion does not "fully" support the guidelines by stating, however, that consumption of foods containing Omega-3 reduces the risk of coronary heart disease. The final sentence in which the authors suggested a revision of the nutrition guidelines no longer appears in the revised article

Increased attention from scientists and journalists

This affair has highlighted, as suggested by Walter Willett, professor at Harvard University, that meta-analysis work is often not applicable to nutrition studies.And, as in this case, some important data are not included in the analysis. In this regard, Robert Heaney, a professor at Creighton University, has published 6 guidelines for researchers that are useful for properly performing meta-analysis in the field of nutrition. According to Willet, among others, the 'article should be withdrawn and not just corrected. Because, while it is true that the finding had great media prominence, raising confusion among consumers, news of the changes related to the study is unlikely to reach them. A gesture of responsibility in the future is demanded not only from scientists, but also from journalists and popularizers. 

Source: Rajiv Chowdhury, MD, PhD; Samantha Warnakula, MPhil; Setor Kunutsor, MD, MSt; Francesca Crowe, PhD; Heather A. Ward, PhD; Laura Johnson, PhD; Oscar H. Franco, MD, PhD; Adam S. Butterworth, PhD; Nita G. Forouhi, MRCP, PhD; Simon G. Thompson, FMedSci; Kay-Tee Khaw, FMedSci; Dariush Mozaffarian, MD, DrPH; John Danesh, FRCP; and Emanuele Di Angelantonio, MD, PhD. "Association of Dietary, Circulating, and Supplement Fatty Acids With Coronary Risk: A Systematic Review and Meta-analysis," Ann Intern Med. 2014;160(6):398-406-406. doi:10.7326/M13-1788