Effects of a Brazilian cardioprotective diet and nuts on cardiometabolic parameters after myocardial infarction: study protocol for a randomized controlled clinical trial

BACKGROUND: Nut consumption has been related to improvements on cardiometabolic parameters and reduction in the severity of atherosclerosis mainly in primary cardiovascular prevention. The objective of this trial is to evaluate the effects of the Brazilian Cardioprotective Diet (DIeta CArdioprotetora Brasileira, DICA Br) based on consumption of inexpensive locally accessible foods supplemented or not with mixed nuts on cardiometabolic features in patients with previous myocardial infarction (MI). METHODS: DICA-NUTS study is a national, multicenter, randomized 16-week follow-up clinical trial. Patients over 40 years old with diagnosis of previous MI in the last 2 to 6 months will be recruited (n = 388). A standardized questionnaire will be applied to data collection and blood samples will be obtained. Patients will be allocated in two groups: Group 1: DICA Br supplemented with 30 g/day of mixed nuts (10 g of peanuts, 10 g of cashew, 10 g of Brazil nuts); and Group 2: only DICA Br. The primary outcome will consist of LDL cholesterol means (in mg/dL) after 16 weeks of intervention. Secondary outcomes will consist of other markers of lipid profile, glycemic profile, and anthropometric data. DISCUSSION: It is expected that DICA Br supplemented with mixed nuts have superior beneficial effects on cardiometabolic parameters in patients after a MI, when compared to DICA Br. TRIAL REGISTRATION: ClinicalTrials.gov Identifier NCT03728127. First register: November 1, 2018; Last update: June 16, 2021. World Health Organization Universal Trial Number (WHO-UTN): U1111-1259-8105. SUPPLEMENTARY INFORMATION: The online version contains supplementary material available at 10.1186/s13063-021-05494-0.