The Acute Effects of Supplementation of Tocotrienols on Insulin Sensitivity and Metabolic Risk Markers in Individuals at Risk for Metabolic Syndrome

• Insulin sensitivity (insulin, glucose) [ Time Frame: 0, 5, 15, 30, 60, 90, 120, 180, 240, 300, 360 min ] [ Designated as safety issue: No ]
• Non-esterified fatty acid (NEFA) [ Time Frame: 0, 5, 15, 30, 60, 90, 120, 180, 240, 300, 360 min ] [ Designated as safety issue: No ]
• Serum triglycerides (TAG) [ Time Frame: 0, 60, 120, 180, 240, 300, 360 min ] [ Designated as safety issue: No ]
• Inflammatory markers (IL-6, IL-1β, TNF-α) [ Time Frame: 0, 120, 240, 360 min ] [ Designated as safety issue: No ]
• PBMC nuclear factor-κappa B (NF-κB) [ Time Frame: 0, 240, 360 min ] [ Designated as safety issue: No ]

Objectives: To compare the acute effects of gamma delta rich tocotrienol fractions (gd-TRF) on insulin sensitivity, metabolic risk markers and postprandial lipemia in individuals at risk for metabolic syndrome.

Hypothesis: Gamma delta-rich TRF will improve insulin sensitivity, metabolic risk markers and postprandial lipemia in individuals at risk for metabolic syndrome.

A randomised, double-blind, crossover trial will be undertaken to test the acute effects of supplementation of 200 mg, 400 mg gd-TRF vs. placebo. There are 3 occasions for subjects to attend during postprandial period and these occasions will be separated by at least one week. On the day preceding the postprandial high fat meal challenge, subjects will be asked to avoid food high in fat, alcohol, caffeine and taking part in any strenuous exercise. Subjects will be provided with a standardised low fat meal (containing < 10 g fat) on the day preceding the postprandial study days to consume as their evening meal. They will be asked to fast overnight and instructed to avoid eating or drinking anything, except water, after 10 pm. Fasting blood samples will be collected on the next day and subjects will then consume the test meal, containing 50 g test fat supplemented with gd-TRF. Further venous blood samples will be collected at regular intervals for up to 6 hours postprandially.

• Dietary Supplement: Gamma delta TRF
  50g of high fat meal will be given in a form of muffin and milkshake. A 200 mg, 400 mg gamma delta TRF or placebo will be incorporated into milkshake.
• Dietary Supplement: Placebo
  50g of high fat meal will be given in a form of muffin and milkshake. A 200 mg, 400 mg gamma delta TRF or placebo will be incorporated into milkshake.

• Experimental: 200 mg gd-TRF
  Intervention: Dietary Supplement: Gamma delta TRF
• Experimental: 400 mg gd-TRF
  Intervention: Dietary Supplement: Gamma delta TRF
• Experimental: Placebo
  Intervention: Dietary Supplement: Placebo

Inclusion Criteria:

• Age: 20-60 years
• BMI ≥ 25 kg/m2
• Elevated triacylglycerols ≥ 1.70 mmol/L
• Low HDL cholesterol < 1.04 mmol/L (men), < 1.30 mmol/L (women)
• Elevated blood pressure ≥ 130/ ≥ 85 mmHg
• Fasting plasma glucose ≥ 5.60 - 7.00 mmol/L
• Increased waist circumference ≥ 90 cm (men), ≥ 80 cm (women)

Exclusion Criteria:

• BMI ≤ 18.5 kg/m2
• Current use of antihypertensive or lipid lowering, insulin/glucose modulating medication
• Lactose/milk intolerance
• Alcohol intake exceeding a moderate intake (> 28 units per week)
• Smoker
• Pregnancy or lactation
• Fever, cold and infection during bleeding day