Consuming pecans as a snack improves lipids/lipoproteins and diet quality compared with usual diet in adults at increased risk of cardiometabolic diseases: a randomized controlled trial

Background: The vascular and cardiometabolic effects of pecans are relatively understudied. Objectives: The aim was to examine how substitution of usual snack foods with 57 g/d of pecans affects vascular health, risk factors for cardiometabolic diseases, and diet quality, compared with continuing usual intake in individuals at risk of cardiometabolic diseases. Methods: A 12-wk single-blinded, parallel, randomized controlled trial was conducted. Adults with ≥1 criterion for metabolic syndrome who were free from cardiovascular disease and type 2 diabetes were included. Participants were provided with 57 g/d of pecans and instructed to replace the snacks usually consumed with the provided pecans. The control group was instructed to continue consuming their usual diet. Flow-mediated dilation (FMD),primary outcome, along with blood pressure, carotid-femoral pulse wave velocity (cf-PWV), lipids/lipoproteins, and glycemic control were measured at baseline and following the intervention. Participants completed 3 24-h recalls at 3 time points (baseline, week 6, and week 12) during the study (9 recalls in total). The Healthy Eating Index-2020 (HEI-2020) was calculated to assess diet quality. Results: In total, 138 participants (mean ± SD; 46 ± 13 y, 29.8 ± 3.7 kg/m²) were randomly assigned (69 per group). No between-group differences in FMD, cf-PWV, or blood pressure were observed. Compared with the usual diet group, pecan intake reduced total cholesterol (−8.1 mg/dL; 95% confidence interval [CI]: −14.5, −1.7), LDL cholesterol (−7.2 mg/dL; 95% CI −12.3, −2.1), non-HDL-cholesterol (−9.5 mg/dL; 95% CI −15.3, −3.7), and triglycerides concentrations (−16.4 mg/dL; 95% CI −30.0, −2.9). Weight tended to increase in the pecan group compared with the usual diet group (0.7 kg; 95% CI −0.1, 1.4). The HEI-2020 increased by 9.4 points (95% CI 5.0, 13.7) in the pecan group compared with the usual diet group. Conclusions: Replacing usual snacks with 57 g/d of pecans for 12-wk improves lipids/lipoproteins and diet quality but does not affect vascular health in adults at risk of cardiometabolic disease. This trial was registered at clinicaltrials.gov as NCT05071807.