Comparison of Low-Fat Versus Mediterranean-Style Dietary Intervention After First Myocardial Infarction (from The Heart Institute of Spokane Diet Intervention and Evaluation Trial)^†

Whether a Mediterranean-style diet reduces cardiovascular events and mortality more than a low-fat diet is uncertain. The objectives of this study were to actively compare low-fat and Mediterranean-style diets after first myocardial infarction (MI) in a randomized, controlled clinical trial and to compare dietary intervention per se with usual care in a case-control analysis. First MI survivors were randomized to a low-fat (n = 50) or Mediterranean-style (n = 51) diet. The 2 diets were low in saturated fat (≤7% kcal) and cholesterol (≤200 mg/day); the Mediterranean-style diet was distinguished by greater omega-3 fat intake (>0.75% kcal). Participants received individual dietary counseling sessions, 2 within the first month and again at 3, 6, 12, 18, and 24 months, along with 6 group sessions. Combined dietary intervention groups (cases, n = 101) were compared with a usual-care group (controls, n = 101) matched for age, gender, MI type and treatment, and status of diabetes mellitus and hypertension. Primary-outcome-free survival (a composite of all-cause and cardiac deaths, MI, hospital admissions for heart failure, unstable angina pectoris, or stroke) did not differ between low-fat (42 of 50) and Mediterranean-style (43 of 51) diet groups over a median follow-up period of 46 months (range 18 to 72; log-rank p = 0.81). Patients receiving dietary intervention had better primary-outcome-free survival (85 of 101) than usual-care controls (61 of 101) (log-rank p <0.001), with unadjusted and adjusted odds ratios of 0.33 (95% confidence interval 0.18 to 0.60, p <0.001) and 0.28 (95% confidence interval 0.13 to 0.63, p = 0.002), respectively. In conclusion, active intervention with either a low-fat or a Mediterranean-style diet similarly and significantly benefits overall and cardiovascular-event-free survival after MI.

• † Conflicts of interest: Dr. Bibus has received consulting fees from companies that make fish oil, Coromega Co., Vista, CA, and Enreco, Inc., Newton, WI. He also has equity ownership in Lipid Technologies, LLC, Austin, MN, the company that performed the plasma fatty acid analysis. Dr. Bibus owns patents related to lipid therapy. He has served as an expert witness regarding lipids and fatty acids.