In this double-blind , randomized , placebo-controlled study , 59 subjects ( 19 males , mean age ( 60.28 6.98 ) years ) with primary hypercholesterolemia ( fasting LDL cholesterol between 3.4-6 .0 mmol/L ) were randomly divided into two groups ( treatment group , 2.5 g of plant sterol esters a day , n = 30 ) and placebo group ( n = 29 ) .