Effect of stanol ester on postabsorptive squalene and retinyl palmitate

Stanol ester dissolved in margarine inhibits cholesterol absorption in gene ral and, despite increasing cholesterol synthesis, decreases serum total an d low-density lipoprotein (LDL) cholesterol levels, but its effects on post prandial lipid metabolism are unknown. We performed fat tolerance tests in 11 men at baseline and during short-term stanol ester consumption without a nd with stanol esters added to the test meal also containing retinol and sq ualene. Cholesterol, triglycerides, retinyl palmitate, and squalene were an alyzed in plasma, chylomicrons, and very-low-density lipoprotein (VLDL) at baseline and 3, 4, 6, 9, 12. and 24 hours after the test meal. Serum total and LDL cholesterol only tended to diminish after the 2-week stanol ester c onsumption. However, the proportion of plasma plant sterol and cholesterol- precursor sterol to cholesterol was significantly altered, suggesting that cholesterol absorption was diminished and cholesterol synthesis was increas ed. Postprandial peak times of squalene and retinyl palmitate in plasma, ch ylomicrons, and VLDL were significantly reduced by stanol esters, but their concentrations in chylomicrons were unchanged. Stanol esters reduced the V LDL squalene peak concentration by 23% (P <.05) and the incremental area un der the curve (AUIC) in plasma and VLDL by 22% and 32% (P <.01 for both). C hylomicron remnant metabolism measured with triglycerides only tended to di minish. The effects of stanol esters in the diet only and both in the diet and with supplementation did not differ significantly. We conclude that die tary stanol esters reduce postprandial lipoproteins measured with dietary r etinyl palmitate and especially squalene, and the reduction is observed eve n though serum total and LDL cholesterol are only inconsistently decreased after short-term stanol ester consumption. Copyright (C) 2000 by W.B. Saund ers Company.