Effects of a diet naturally rich in polyphenols on lipid composition of postprandial lipoproteins in high cardiometabolic risk individuals: an ancillary analysis of a randomized controlled trial

Plasma lipoprotein composition, especially in the postprandial state, could be relevant for cardiovascular risk and could be influenced by eating habits. This study evaluated the effects of a polyphenol-rich diet on postprandial lipoprotein composition in individuals at high cardiometabolic risk. Seventy-eight individuals with high waist circumference and at least another component of the metabolic syndrome were randomized to either a high-polyphenol (HighP) or low-polyphenol (LowP) diet. Before and after the 8-week intervention, chylomicrons, VLDL1, VLDL2, IDL, LDL, HDL particles, and their lipid concentrations were determined over a 6-h high-fat test meal with high or low-polyphenol content, according to the diet assigned. VLDL1 postprandial areas under the curve (AUCs) were lower for cholesterol (Chol) (1.48 ± 0.98 vs. 1.91 ± 1.13 mmol/L × 6 h, M ± SD, p = 0.014) and triglycerides (Tg) (4.70 ± 2.70 vs. 6.02 ± 3.07 mmol/L × 6 h, p = 0.005) after the HighP than after the LowP diet, with no changes in Chol/Tg ratio. IDL Chol AUCs were higher after the HighP than after the LowP diet (1.29 ± 0.77 vs. 1.01 ± 0.51 mmol/L × 6 h, p = 0.037). LDL Tg AUCs were higher after the HighP than after the LowP diet (1.15 ± 0.33 vs. 1.02 ± 0.35 mmol/L × 6 h, p < 0.001), with a lower Chol/Tg ratio (14.6 ± 4.0 vs. 16.0 ± 3.8, p = 0.007). HDL Tg AUCs were lower after the HighP than after the LowP diet (1.20 ± 0.41 vs. 1.34 ± 0.37 mmol/L × 6 h, p = 0.013). A high-polyphenol diet reduces the postprandial lipid content of large VLDL and increases IDL cholesterol; it modifies the composition of LDL particles—which become richer in triglycerides, and of HDL—which become instead triglyceride poor. The overall changes in atherogenicity by these effects warrant further investigation on clinical cardiovascular outcomes.