Published
Objectives: The objective was to study the relative effect of tocotrienol supplements of different compositions (mixed alpha- plus gamma-, high gamma-, or P25-complex tocotrienol) on blood lipids, fasting blood glucose, and the excretion of 8-iso-prostaglandin F(2alpha), a measure of oxidative stress, in healthy hypercholesterolemic men and women.
Study design: Double-blind, randomized, parallel-design study
Subjects: Healthy hypercholesterolemic subjects
Intervention: Mixed tocotrienol versus placebo (safflower oil)
Primary outcome: Fasting blood lipids, fasting blood glucose, and the excretion of 8-iso-prostaglandin F(2alpha), a measure of oxidative stress.
Methodology: In this study, subjects consumed 1 of 3 commercially available tocotrienol supplements or a safflower oil placebo for 28 days. Blood and urine samples were obtained before and after the 28-d supplementation phase for analysis of fasting blood lipids, glucose, tocotrienols and tocopherols, and 8-iso-prostaglandin F(2alpha).
Results: Overall, serum tocotrienols were increased in subjects who consumed tocotrienols, which showed that the putatively active components were absorbed. No significant differences in mean lipid or glucose concentrations were observed among the 4 treatment groups at the end of the 28-dsupplementation phase. However, when the values were expressed as a percentage change from the concentrations during the presupplementation run-in phase, LDL cholesterol increased slightly (7 +/- 2%) but significantly (P < 0.05) in the group consuming the mixed alpha- plus gamma-tocotrienol supplement when compared with LDL cholesterol in the group consuming the P25-complex tocotrienol. Neither mean concentrations nor the percentage change in 8-iso-prostaglandin F(2alpha) differed significantly among treatments.
Conclusion: Supplementation with 200 mg tocotrienols/d from 3 commercially available sources has no beneficial effect on key cardiovascular disease risk factors in highly compliant adults with elevated blood lipid concentrations.