Short term effects of palm-tocotrienol and palm-carotenes on vascular function and cardiovascular disease risk: A randomised controlled trial.

Background And Aims: In vitro, ex vivo and animal studies suggest palm-based tocotrienols and carotenes enhance vascular function, but limited data in humans exists. The aim was to examine the effects of palm-tocotrienols (TRF- 80) and palm-carotene (CC-60) supplementation on vascular function and cardiovascular disease (CVD) risk factors in adults at increased risk of impaired vascular function.

Methods: Ninety men and women (18-70 yr, 20-45 kg/m) with type 2 diabetes, impaired fasting glucose and/or elevated waist circumference were randomised to consume either TRF-80 (420 mg/day tocotrienol + 132 mg/day tocopherol), CC-60 (21 mg/day carotenes) or placebo (palm olein) supplements for 8 weeks. Brachial artery flow-mediated dilation (FMD), other physiological and circulatory markers of vascular function, lipid profiles, glucose, insulin and inflammatory markers were assessed pre- and post-supplementation. Pairwise comparisons were performed using mixed effects longitudinal models (n = 87, n = 3 withdrew before study commencement).

Results: Plasma α- and β-carotene and α-, δ- and γ-tocotrienol concentrations increased in CC-60 and TRF-80 groups, respectively, compared to placebo (mean ± SE difference in total plasma carotene change between CC-60 and placebo: 1.5 ± 0.13 μg/ml, p < 0.0001; total plasma tocotrienol change between TRF-80 and placebo: 0.36 ± 0.05 μg/ml, p < 0.0001). Neither FMD (treatment x time effect for CC-60 vs. placebo, p = 0.71; TRF-80 vs. placebo, p = 0.80) nor any other vascular function and CVD outcomes were affected by treatments.

Conclusions: CC-60 and TRF-80 supplementation increased bioavailability of palm-based carotenes and tocotrienols but had no effects, superior or detrimental, on vascular function or CVD risk factors.