ABSTRACT
OBJECTIVE: Black raspberry (Rubus occidentalis) has been known for its anti-inflammatory and anti-oxidant effects and for improving vascular endothelial function in patients at high-risk for cardiovascular disease. We investigated short-term effects of black raspberry on lipid profiles, vascular endothelial function and circulating endothelial progenitor cells in statin naïve participants with metabolic syndrome. METHODS: Patients with metabolic syndrome (n=51) without lipid lowering medications were prospectively randomized into the black raspberry group (n=26, 750 mg/day) and placebo group (n=25) during the 12-week follow-up. Lipid profiles, brachial artery flow-mediated dilatation (baFMD) and inflammatory cytokines such as IL-6, TNF-α, C-reactive protein, adiponectin, sICAM-1, sVCAM-1 were measured at baseline and at 12-week follow-up. Central blood pressure and augmentation index were also measured at baseline and at 12-week follow-up. RESULTS: Decreases from baseline in total cholesterol levels (-22.7±34.3 mg/dL vs. 0.0±34.7mg/dL, p<0.05, respectively) and total cholesterol/HDL ratio (-0.34±0.68 vs. 0.17±0.56, p<0.05, respectively) were significantly greater in the black raspberry group when compared to the placebo group. Decreases from baseline in IL-6 (-0.5±1.4 pg/mL vs. -0.1±1.1 pg/mL, p<0.05, respectively) and TNF-α levels (-5.4±4.5 pg/mL vs. -0.8±4.0 pg/mL, p<0.05, respectively) were significantly greater in the black raspberry group. Increases from the baseline in adiponectin levels (2.9±2.1 µg/mL vs. -0.2±2.5 µg/mL, p<.05) were significant in the black raspberry group. Increases in baFMD at 12-week follow-up were significantly greater in the black raspberry group when compared to the placebo group (2.9±3.6 mm vs. 1.0±3.9 mm, p<0.05, respectively). Radial augmentation indexes were significantly decreased in the black raspberry group when compared to the placebo group (-2±10% vs. 4±13%, p<0.05). CONCLUSION: The use of black raspberry significantly decreased serum total cholesterol levels, inflammatory cytokines, and augmentation index, thereby improving vascular endothelial function in statin naïve participants with metabolic syndrome during the 12-week follow-up.