Impact of Consuming Plant Sterols on Endothelial Function and Blood Pressure

The purpose of the research is to assess the impact of co-consuming plant sterols-enriched food product as part of a healthy eating pattern diet on endothelial function (brachial artery FMD, vasodilation-related and vasoconstriction-related biomarkers) and blood pressure management (24-hour ambulatory and classic blood pressure) in Singapore individuals with MetS.

This is a 13-wk double-blinded, randomized, crossover study design. Following a 1-wk pre-intervention baseline period, subjects will be randomly assigned to follow a healthy eating pattern diet either contain 2.0 g free plant sterols equivalent of their palmityl esters (Plant Sterol Diet) or do not contain plant sterols (Control Diet) for 4 weeks. After a 4-week dietary 'washout' period, they will consume the alternative diet for 4 weeks. The random assignment will be done with SAS 9.4 software. Body size measurement, dietary assessment, brachial artery FMD and blood pressure measurements, and fasting-state blood collection will be conducted at week 1, 5, 9, and 13, which correspond to before and during the last 1 week of the two 4-week intervention periods.

During study week 1 and weeks 6-9, all subjects will consume their habitual, unrestricted self-chosen diets. During study weeks 2-5 and 10-13, all subject will follow a healthy eating pattern diet, referred to as the "My Healthy Plate" designed by HPB. Each subject's energy requirement will be estimated using sex-specific equations and Recommended Dietary Allowances for healthy Singaporean. One-on-one dietary counselling and written instructions for each subject will be provided by a research dietitian and trained research staff to achieve a healthy eating pattern diet. Compliance with the plant sterols consumption will be promoted by frequent online and in-person contact.

Eligibility Criteria:
Inclusion Criteria:

1. Ability to give an informed consent;
2. Age\>35 years old;
3. Meet any 3 of the 5 following NCEP-ATP III MetS criteria (waist circumference \> 90 cm (male), \> 80 cm (female); fasting glucose concentration ≥ 100 mg/dL or on medication; triglyceride ≥ 150 mg/dL or on medication; high density lipoprotein cholesterol (HDL) \< 40 mg/dL (male), \< 50 mg/dL (female); systolic or diastolic blood pressure \> 130/80 mmHg or on medication);
4. Weight change \< 3kg in the past 3 months;
5. No exercising vigorously over the past 3 months;
6. No allergy to plant sterols; no acute illness; not smoking;
7. No drinking more than 2 alcoholic drinks per day;
8. No pregnant, lactating, or planning pregnancy in the next 6 months.

Exclusion Criteria:

1. Unable to give an informed consent;
2. Age\<35 years old;
3. Meet less than 3 of following NCEP-ATP III MetS criteria (waist circumference \> 90 cm (male), \> 80 cm (female); fasting glucose concentration ≥ 100 mg/dL or on medication; triglyceride ≥ 150 mg/dL or on medication; high density lipoprotein cholesterol (HDL) \< 40 mg/dL (male), \< 50 mg/dL (female); systolic or diastolic blood pressure \> 130/80 mmHg or on medication);
4. Weight change \> 3kg in the past 3 months;
5. Exercise vigorously over the past 3 months;
6. Allergy to plant sterols; no acute illness; not smoking;
7. Drinking more than 2 alcoholic drinks per day;
8. Pregnant, lactate, or plan pregnancy in the next 6 months.