BACKGROUND: Pecan consumption consistently improves lipoproteins, but less research has investigated the effect of pecans on lipoprotein subfractions. OBJECTIVES: The aim was to investigate the effect of substitution of usual snack foods with 57 g/day of pecans on lipoprotein particle subfractions and apolipoproteins compared to continuing usual intake after 12 weeks. Exploratory analyses evaluated effects on early markers of insulin resistance including the Lipoprotein Insulin Resistance Index (LP-IR), Diabetes Risk Index (DRI), and GlycA. METHODS: A 12-week, randomized, 2-armed parallel trial in adults at risk for cardiometabolic disease was conducted. Participants were instructed to either consume 57 g/day of pecans in place of usual snacks or to continue usual intake. Plasma samples collected at baseline and 12 weeks were analyzed for lipoproteins, apolipoproteins and GlycA by proton nuclear magnetic resonance spectroscopy. Between-group differences in the change from baseline were evaluated with linear regression. RESULTS: In total, 138 participants were randomized (n=69 per group) and 130 participants (pecan group n=62
usual diet group n=68) completed the trial. The pecan group had a greater reduction from baseline in the concentrations of apolipoprotein B (apoB) (-4.38 mg/dL
95%CI -8.02, -0.73), total LDL (-75.3 nmol/L
95%CI -144, -6.93), total triglyceride rich lipoproteins (TRL-P) (-20.4 nmol/L
95%CI -33.8, -7.03), large (-1.47 nmol/L
95%CI -2.69, -0.26) and small (-11.3 nmol/L
95%CI -22.4, -0.27) TRL-P and the LP-IR (-4.42 points
95%CI -8.14, -0.69), and greater increases from baseline in the concentration of large high density lipoproteins (0.35 μmol/L
95%CI 0.07, 0.63) compared to the usual diet group. CONCLUSIONS: Incorporating 57 g/day of pecans into the diet in place of usual snacks for 12 weeks improved apoB, atherogenic lipoprotein subfractions, and the LP-IR in adults at risk for cardiometabolic diseases. CLINICAL TRIALS REGISTRATION: https://clinicaltrials.gov/study/NCT05071807
NCT05071807.