The role of plant sterols in cardiovascular diseases is controversially debated. There is an increasing body of evidence that indicates that increased plant sterol serum concentrations are correlated with an increased cardiovascular risk. Functional foods such as margarines supplemented with plant sterol esters are advertised to patients with hypercholesterolemia. Numerous studies show that margarines supplemented with plant sterol esters reduce serum cholesterol concentrations significantly. However, there are no studies available investigating relevant clinical endpoints. Nor are there any studies availabe investigating the effect of the consumption of margarines supplemented with plant sterol esters on serum and cardiovascular tissue concentrations. This study is done to investigate the effect of margarines supplemented with plant sterol esters on serum and cardiovascular tissue concentrations.