Comparison of the Efficacy of Plant Sterol-Enriched Soymilk Versus Plain Soymilk in Volunteers With High LDL-Cholesterol

This was a multicenter, prospective, randomized, double-blinded, controlled-trial study in hypercholesterolemic volunteers (serum LDL-C > 130 mg/dL). After initial assessment at the screening period, eligible subjects were randomized to receive either plant sterol and soluble fiber-enriched soymilk (SFSM) or plain soymilk (SM) 360 mL/day (2 packages a day) for 8 weeks. The participants might take the study product as snack, the first one in the morning and the second one in the afternoon. It was possible to take it before or after meal, however taken before meal was highly suggested. A physical examination (including vital signs, height, weight, body mass index, waist circumference, and systemic evaluation) was performed at each visit, every 2 weeks. Concurrent medications usage were record at each visit during the study as well.

Three-day per week of food intake and weekly exercises were recorded and evaluated at every visit. It was recommended every participant to follow dietary control and lifestyle modification to improve hypercholesterolemia during the entire study. Details of overall product satisfaction were evaluated by the participants after 2 and 8 weeks of study products consumption (at visit 2 and 5). To evaluate compliance, the participants were asked to collect and return the empty packages to the investigator every 2 weeks at visit 2, 3, 4, and 5. More than 90% of study product consumption would be considered as eligible on-going subjects.

Venous blood samples were collected from the eligible subjects during pre-treatment (screening period; day -7), every 2 week after treatment (visit 2, 3, 4, 5; at the end of week 2, 4, 6 and 8) to test for lipid profiles and fasting blood sugar (FBS). Adverse events, if any, were recorded immediately after study enrollment.

Inclusion criteria

• Healthy male or female, age > 18 years
• If female, subject is either post-menopausal or surgically sterilized, or has a negative urine pregnancy test within 7 days prior to enrollment and will use adequate contraception during the study
• Has LDL-C > 130 mg/dL
• If subject has been treated with cholesterol-lowering agents prior to admission, he/she must have taken medication regularly at a stable dose for at least 8 weeks
• Provided written informed consent prior to admission to the study.

Exclusion criteria

• Has history of organ transplantation
• Hypersensitivity to soy bean or has specific allergy to the ingredients of soymilk
• Has taken any medication that affects serum cholesterol level, such as oral contraceptive pills, high dose diuretics or beta-blockers, antiretroviral protease inhibitors, tegretol, and anabolic steroids, unless these drugs have been consumed at the same dosage for > 8 weeks prior to admission of the study
• Has serum triglyceride ≥ 400 mg/dL
• Immunocompromised status, including a debilitated state or malignancy
• Has consumed any immunosuppressive agents such as cyclosporine, tacrolimus, azathioprine, and chemotherapeutic agents
• Active liver, renal or thyroid diseases
• Recent myocardial infarction or stroke within 3 months prior to admission
• Has recently been admitted in the hospital due to any illness within 2 months prior to admission
• Frequent alcoholic consumption > 2 a week; with beer > 360 mL, alcohol > 45 mL, wine > 150 mL for female, or beer > 720 mL, whisky > 90 mL, wine > 300 mL for male each time
• HasGI symptoms such as nausea, vomiting, loss of appetite, premature satiety, diarrhea, or chronic constipation
• Consume study product less than 90% during in treatment period
• Pregnancy or breast feeding woman
• Has previously been admitted to this study
• Lack of ability or willingness to give informed consent
• Start taking any medication that may affect serum lipid profiles or immunosuppressive agents during in the study
• Receiving dietary supplement with plant sterols/ stanols and/ or fiber.