Scientific Study

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/d of pecans on lipoprotein particle subfractions and apolipoproteins compared with continuing usual intake after 12 wk. Exploratory analyses evaluated effects on early markers of insulin resistance including the Lipoprotein Insulin Resistance Index (LP-IR), Diabetes Risk Index, and GlycA. Methods: A 12-wk, randomized, 2-armed parallel trial in adults at risk of cardiometabolic disease was conducted. Participants were instructed to either consume 57 g/d of pecans in place of usual snacks or to continue their usual intake. Plasma samples collected at baseline and 12 wk 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 randomly assigned (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% confidence interval (CI): -8.02, -0.73], total low-density lipoprotein particles (-75.3 nmol/L; 95% CI: -144, -6.93), total triglyceride-rich lipoprotein particles (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 lipoprotein particles (0.35 μmol/L; 95% CI: 0.07, 0.63) compared with the usual diet group. Conclusions: Incorporating 57 g/d of pecans into the diet in place of usual snacks for 12 wk improved apoB, atherogenic lipoprotein subfractions, and the LP-IR in adults at risk of cardiometabolic diseases. This trial was registered at clinicaltrials.gov as NCT05071807.

https://doi.org/10.1016/j.tjnut.2025.03.014