The Chain Length of Dietary Saturated Fatty Acids Affects Human Postprandial Lipemia

Objective: Saturated fats increase total cholesterol (TC) and low density lipoprotein-cholesterol (LDL-C) and are linked to coronary artery disease risk. The effect of variance in chain length of saturated fatty acids (SFA) on coronary artery disease in human postprandial lipemia is not well elucidated. Methods: A total of 20 healthy volunteers were challenged with 3 test meals, similar in fat content (similar to 31% en) but varying in saturated SFA content and polyunsaturated/saturated fatty acid ratios (P/S). The 3 meals were lauric myristic acid-rich (LM), P/S 0.19; pahnitic acid-rich (POL), P/S 0.31; and stearic acid-rich (STE), P/S 0.22. Blood was sampled at fasted baseline and 2, 4, 5, 6, and 8 hours. Plasma lipids (triacylglycerol [TAG]) and lipoproteins (TC, LDL-C, high density lipoprotein-cholesterol [HDL-C]) were evaluated. Results: Varying SFA in the test meal significantly impacted postprandial TAG response (p < 0.05). Plasma TAG peaked at 5 hours for STE, 4 hours for POL, and 2 hours for LM test meals. Area-under-the-curve (AUC) for plasma TAG was increased significantly after STE treatment (STE > LM by 32.2%, p = 0.003; STE > POL by 27.9%, p = 0.023) but was not significantly different between POL and LM (POL > LM by 6.0%, p > 0.05). At 2 hours, plasma HDL-C increased significantly after the LM and POL test meals compared with STE (p < 0.05). In comparison to the STE test meal, HDL-C AUC was elevated 14.0% (p = 0.005) and 7.6% (p = 0.023) by the LM and POL test meals, respectively. The TC response was also increased significantly by LM compared with both POL and STE test meals (p < 0.05). Conclusions: Chain length of saturates clearly mediated postmeal plasma TAG and HDL-C changes.