Letters Section Editor: Jody W. Zylke, MD, Senior Editor.
Author Affiliations: Division of Cardiovascular Medicine, Brigham and Women's Hospital, Boston, Massachusetts (Dr Mozaffarian; firstname.lastname@example.org); and Department of Clinical Pharmacology and Epidemiology, Consorzio Mario Negri Sud, Santa Maria Imbaro, Italy (Dr Marchioli).
In Reply: Dr Cleland and colleagues suggest that ineffectiveness of fish oil in the Omega-3 Fatty Acids for Prevention of Post-operative Atrial Fibrillation (OPERA) trial and other trials might relate to equally potent benefits of olive oil used as placebo in these studies. To address the plausibility of this idea, 3 issues must be considered: the evidence for olive oil's cardiovascular benefits; the dose response of such effects; and whether existing trial data support this hypothesis.
Mozaffarian D, Marchioli R. Fish Oil vs Olive Oil for Postoperative Atrial Fibrillation—Reply. JAMA. 2013;309(9):871-872. doi:10.1001/jama.2013.673