Effect of Plant Sterol Enriched Milk on Plasma Lipid Levels of Humans Breast-fed During Infancy

Effect of a Plant Sterol-Fortified Low-fat Milk Product on Plasma Lipid Levels of Humans in Relation to Different Infant Feeding Practices and Later Life Cholesterol Metabolism

The overall goal of this clinical study is to investigate how dietary cholesterol intake influences the plasma Total cholesterol (TC), LDL-Cholesterol levels and cholesterol metabolism between adults who had been breast-fed as infants as a function of the duration of breast feeding and quantity of early cholesterol intake. The study also aims to evaluate the effect of a plant sterol formulation in low fat milk shake in modulating the lipid profile favorably in the study population.

Hypothesis 1: To determine the responsiveness of plasma lipid profile including Total cholesterol and LDL cholesterol concentrations to high and low cholesterol diets in adults who been breast-fed as infants for different durations

Hypothesis 2: To determine if differences exist in rates of cholesterol absorption and synthesis in adults, and whether such differences respond to variations in cholesterol intake, between individuals who were breast for different durations.

Hypothesis 3: Consumption of a plant sterol formulation in low-fat milk product will favorably alter lipid profiles compared with control in the study population.

This is a free-living, randomized, crossover trial. This trial is modeled after previously successful functional food trial at the investigators clinic, consistent with current recommendations to decrease Cardiovascular diseases (CVD) risk and improve circulating lipid profiles. The proposed study will include three treatment phases of 4 weeks each, separated by 4-week washout intervals:

Phase 1: Study diets with placebo (240 ml of 2% milk shake; 50 mg cholesterol).

Phase 2: Study diets with enriched cholesterol (240ml of 2% milk shake; 600 mg cholesterol).

Phase 3: A study diet with plant sterols (240 ml of 2% milk shake;2.0 g/d of plant sterols/240 ml serving; 50 mg cholesterol).

During each treatment period participants will consume their supper time meal along with assigned test product. Consumption of the suppertime meals and the test products will be monitored by a clinical coordinator to ensure compliance. Participants will be asked to fill out a 3-day food diary at the beginning and end of each experimental period.

Inclusion Criteria:

• Triglycerides (TG) <3.0 mmol/L
• Body mass index (BMI) between 20 and 30 kg/m2
• Participants must have been breast-fed at least during the first 6 months of their life

Exclusion Criteria:

• History of recent (i.e. less than 1 month) or chronic use of oral hypolipidemic therapy, including fish oils, or probucol within the last 3 months
• History of chronic use of alcohol (>2 drinks/d), smoking, systemic antibodies, corticosteroids, androgens, or phenytoin
• Myocardial infarction, coronary artery bypass, kidney disease, liver disease or other major surgical procedures within the last six months,
• Sitosterolemic patients
• Recent onset of angina, congestive heart failure, inflammatory bowel disease, pancreatitis, diabetes, or significant current (i.e. onset within past three months) gastrointestinal, renal, pulmonary, hepatic or biliary disease, or cancer (evidence of active lesions, chemotherapy or surgery in the past year)
• Exercise greater than walking or running 15 miles/wk or 4,000 kcal/wk
• Participants who have not been breast-fed at all
• Pregnant or planning for pregnancy during the next 5 month period