Cholesterol-Absorber Status Modifies the LDL Cholesterol-Lowering Effect of a Mediterranean-Type Diet in Adults with Moderate Cardiovascular Risk Factors

LDL-cholesterol (LDL-C) reduction may be achieved by various types of prudent diets, but their effects on surrogate markers of cholesterol absorption and synthesis have not been well studied in humans. We aimed to assess whether the extent of cholesterol absorption or synthesis, and cholesterol concentrations, are modified in adults when they shift from a Western-type diet (WD) to a combined low-fat, low-cholesterol/Mediterranean-type diet (LFCMD). Cholestanol and sitosterol, as well as desmosterol and lathosterol, surrogate markers of cholesterol absorption or synthesis, respectively, were quantified in the serum of 125 fasting, middle-aged participants at moderate cardiovascular risk. They habitually consumed a WD and then consumed a LFCMD during the 3-mo intervention. The group was stratified by serum cholestanol concentration and classified as high, intermediate, or low absorbers of cholesterol. When they consumed the WD, participants had comparable total and LDL-C concentrations, independent of absorber group and sex. After 3 mo of consuming the LFCMD, absorption and synthesis did not change or changed only slightly. The cholestanol concentration increased in low absorbers by 18% (P < 0.02) and decreased in high absorbers by 14% (P < 0.001), but these variations did not change the high- or low-absorber status. In male and female low absorbers, plasma total (-7%) and LDL-C (-9%) concentrations decreased after the 3-mo intervention and changes were 2.3- and 2.4-fold greater, respectively, than in high absorbers, independent of sex. Cholesterol synthesis/absorption status was not markedly altered by diet, but the decrease in plasma LDL-C due to the Mediterranean-type diet occurred only in low absorbers of cholesterol. This should be considered during further dietary interventions. J. Nutr. 141: 1791-1798, 2011.