Olive Oil Consumption and Advanced Lipoprotein Subclass Profile: A Propensity Score-Matched Analysis from the Di@bet.es Population-Based Study

Background/Objectives: Standard lipid profiling only partially captures the atherogenic risk conferred by lipoprotein heterogeneity. We investigated the association between olive oil consumption and both the standard lipid profile and the advanced lipoprotein subclass profile in a Spanish population-based cohort. Methods: In this cross-sectional analysis of the Di@bet.es study (n = 3123 after exclusions), 98 participants who reported never using olive oil were matched 1:1 by propensity score (nearest neighbor, caliper 0.2 SD; age, sex, BMI, sweets and carbohydrate intake, waist and hip circumference, physical activity, alcohol, and smoking) to 98 participants who always or usually used olive oil. Lipoprotein subclasses were quantified by 1H-NMR spectroscopy (Liposcale®). Groups were compared using Student’s t-test or the Mann–Whitney U test; p-values were adjusted with the Benjamini–Hochberg procedure. Results: Olive oil users had a lower concentration of medium VLDL particles (−28%; p = 0.002; adjusted p = 0.024). Total VLDL-P, VLDL-TG, total triglycerides, and HDL TG/C were nominally lower and HDL-c higher (p = 0.035–0.049), but none remained significant after adjustment (adjusted p ≥ 0.112). The derived TG/HDL-c ratio, a single unadjusted comparison, was also lower (p = 0.022). No differences in total cholesterol, LDL-c, or LDL and HDL particle number were found. Conclusions: Olive oil use was associated with a lower concentration of medium VLDL particles, without differences in LDL-c. Given the cross-sectional design and small matched sample, these exploratory findings do not establish causality or support clinical use of NMR profiling.