Health effects of sterols

Cholesterol-lowering mechanism of plant sterols and stanols 

The precise mechanism of cholesterol transport from the micelles into the 

This decrease in absorption applies to both dietary and endogenously synthesized biliary cholesterol (Gylling et al., 1997), which explains why plant sterols and stanols have an effect even in those consuming low-cholesterol 

Several mechanisms by which plant sterols might affect cholesterol absorption have been proposed (Poliak and Kritchevsky, 1981 Ling andJones, 1995). The interference with intestinal cholesterol absorption by plant sterols is probably related to the close resemblance in the chemical structures of these molecules, although the precise mechanisms are not yet fully understood. At present, reduced micellar solubility of cholesterol is thought to be the main mechanism by which plant sterols reduce cholesterol absorption. Ikeda et al. (1989) elegantly proved that cholesterol solubility in mixed micelles is reduced by plant sterols and plant stanols, in studies on rats. For 10 days rats were fed a diet enriched with cholesterol (0.5%, w/w of diet) alone, or together with 

Another possible mechanism by which plant sterols and stanols may interfere with cholesterol absorption is that they reduce the amount of free cholesterol in the micellar phase by inhibiting the hydrolysis of cholesterol esters. Miettinen et al. (2001) showed that plant stanol esters reduced the amount of free cholesterol in the micellar phase by 34%, but increased the amount of esterified cholesterol in the micellar and oil phases from 10% to 35%. 

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