Encapsulated oil palm phenolics lower blood pressure and improve antioxidant status in healthy adults: a phase one trial

Oil Palm Phenolics (OPP), derived from by-products of oil palm fruit processing, contain bioactive polyphenols with nutraceutical benefits. While the optimal dose has been suggested for both liquid and spray-dried preparations, their efficacy in humans requires further investigation. This study assesses the effects of encapsulated OPP powder on cardiovascular and antioxidant (AOX) parameters in healthy individuals. A double-blind, placebo-controlled trial with 97 healthy volunteers randomized into four groups: placebo, 250 mg, 1000 mg, and 1500 mg/d spray-dried encapsulated OPP for 60 days. Primary outcomes included changes in lipid profiles, systolic (SBP) and diastolic blood pressure (DBP), and AOX markers including glutathione peroxidase (GSH-Px), glutathione reductase (GR), total superoxide dismutase (T-SOD), and total AOX capacity (T-AOC). 250 mg/d OPP significantly reduced SBP and DBP at day 60 compared to baseline (SBP: p = 0.017; DBP: p < 0.001). T-AOC improved significantly with the 1500 mg/d at day 30 (p = 0.038). Higher doses OPP (1000 and 1500 mg/d) preserved GSH-Px levels, while placebo and 250 mg/d OPP showed declines. Encapsulated OPP improved AOX status without affecting lipid profiles while improves BP at low doses. These findings support its development as a dietary supplement, warranting further investigation into optimized dosages and long-term effects.