Low and moderate-fat plant sterol fortified soymilk in modulation of plasma lipids and cholesterol kinetics in subjects with normal to high cholesterol concentrations: report on two randomized crossover studies.
BACKGROUND
Although consumption of various plant sterol (PS)-enriched beverages is effective in lowering plasma cholesterol, the lipid-lowering potential of PS in a soymilk format has not been investigated thoroughly. Therefore, to evaluate the efficacy of PS-enriched soy beverages on plasma lipids and cholesterol kinetics, we conducted two separate 28 d dietary controlled cross-over studies. In study 1, the cholesterol-lowering efficacy of a low-fat (2 g/serving) PS enriched soy beverage was examined in 33 normal cholesterolemic subjects in comparison with 1% dairy milk. In study 2, we investigated the efficacy of a moderate-fat (3.5 g/serving) PS-enriched soy beverage on plasma cholesterol concentrations and cholesterol kinetic responses in 23 hypercholesterolemic subjects compared with 1% dairy milk. Both the low and moderate-fat PS-enriched soymilk varieties provided 1.95 g PS/d. Endpoint plasma variables were analyzed by repeated-measures ANOVA using baseline values as covariates for plasma lipid measurements.


RESULTS
In comparison with the 1% dairy milk control, the low-fat soy beverage reduced (P < 0.05) total and LDL-cholesterol by 10 and 13%, respectively. Consumption of the moderate-fat PS-enriched soy beverage reduced (P < 0.05) plasma total and LDL-cholesterol by 12 and 15% respectively. Fasting triglycerides were reduced by 9.4% following consumption of the moderate-fat soy beverage in comparison with the 1% dairy milk. Both low and moderate-fat PS-enriched soy varieties reduced (P < 0.05) LDL:HDL and TC:HDL ratios compared with the 1% dairy milk control. Consumption of the moderate-fat PS-enriched soymilk reduced (P < 0.05) cholesterol absorption by 27%, but did not alter cholesterol synthesis in comparison with 1% dairy milk.


CONCLUSIONS
We conclude that, compared to 1% dairy milk, consumption of low and moderate-fat PS-enriched soy beverages represents an effective dietary strategy to reduce circulating lipid concentrations in normal to hypercholesterolemic individuals by reducing intestinal cholesterol absorption. TRIAL REGISTRATION (CLINICALTRIALS.GOV): NCT00923403 (Study 1), NCT00924391 (Study 2).
Rideout
Todd C
TC
Richardson Centre for Functional Foods and Nutraceuticals, University of Manitoba, Winnipeg, Manitoba R3T6C5, Canada. t_rideout@umanitoba.ca
Chan
Yen-Ming
YM
Harding
Scott V
SV
Jones
Peter Jh
PJ
D002784:Cholesterol / Q000097:blood*; D008078:Cholesterol, LDL / Q000097:blood; D018592:Cross-Over Studies; D004041:Dietary Fats / Q000008:administration & dosage / Q000494:pharmacology*; D006801:Humans; D006937:Hypercholesterolemia / Q000178:diet therapy; D007700:Kinetics; D008055:Lipids / Q000097:blood*; D010840:Phytosterols / Q000008:administration & dosage / Q000494:pharmacology*; D041942:Soy Milk / Q000008:administration & dosage / Q000737:chemistry / Q000494:pharmacology*
D008078:Cholesterol, LDL; D004041:Dietary Fats; D008055:Lipids; D010840:Phytosterols; D002784:Cholesterol