Soy Protein Enhances Cholesterol-Lowering Power of Plant Sterol Esters

VLAARDINGEN, The Netherlands--A combination of plant sterol esters and soy protein significantly reduced plasma cholesterol compared to each individually, according to a study published in the January issue of the Journal of Nutrition (134:143-8, 2004) (www.nutrition.org). Researchers from Unilever Health Institute fed hamsters diets containing casein or soy protein with or without plant sterol esters for five weeks. Compared with the control casein diet, 0.24 g/100 g diet of PSE and 20 g/100 g diet of soy protein (in place of casein) each lowered plasma total cholesterol by 13 percent and 9 percent, respectively. In combination, PSE and soy protein decreased plasma total cholesterol by 26 percent, with reduction primarily in the non-HDL fraction. The combination also reduced plasma triacylglycerol concentration by 37 percent.

Researchers noted PSE increased fecal excretion of neutral sterols by 190 percent and soy protein increased such excretion by 66 percent. They concluded, "The combination of PSE and soy protein more dramatically lowers plasma lipids than the individual ingredients."