Cholesterol-lowering properties of plant sterols esterifiedwith beef tallow fatty acids in hamsters

Plant sterol esters (PSE) reduce plasma low-density lipoprotein cholesterol concentration by inhibiting cholesterol absorption. Previous work in our laboratory indicated that PSE containing stearic acid (SA), compared to linoleic acid, were significantly more effective at reducing cholesterol absorption. We tested the cholesterol lowering properties of PSE containing fatty acids from beef tallow, a natural and abundant source of SA. Male hamsters were fed diets containing 0.0%, 0.5%, 1.0%, or 5.0% beef tallow PSE for 4 weeks. Dose-dependent reductions (P < .05) were observed in cholesterol absorption, liver esterified cholesterol, and plasma nonhigh-density lipoprotein cholesterol concentration; hamsters fed 5.0% PSE exhibited reductions of 56%, 98%, and 38%, respectively, compared to controls. Concurrent increases (P < .05) in fecal sterol excretion were also observed. In a second hamster study, the cholesterol-lowering properties of beef tallow PSE were compared to hamsters fed molar equivalents of free plant sterols (PS) and free SA. Beef tallow PSE were significantly more effective at reducing liver and plasma cholesterol concentrations than PS and SA consumed individually. Whether PS and SA act through independent or synergistic mechanisms will require further research, although the present findings support the use of dietary PSE containing beef tallow fatty acids in the management of hypercholesterolemia.