A nutritional product designed to enhance nitric oxide actvity restores endothelium-dependent function in hypercholesterolemia

Background: We investigated the vascular and biochemical effects of a nutrient bar enriched with L-arginine and a combination of other nutrients known to enhance the synthesis or activity of endothelium-derived nitric oxide. Methods: Using a single-blind dose-response design, 41 individuals with hypercholesterolemia were assigned to consume 2 or 3 bars/day for 2 weeks. Each bar contains 4g of L-arginine as well as antioxidant vitamins, niacin and isoflavenoids. Flow-mediated (endothelium-dependent) and nitroglycerin-mediated (endothelium-independent) vasodilation of the brachial artery was measured using high-resolution ultrasonography before and after intervention. Results: Before 2 or 3 bar/day intervention, mean serum arginine level was 33 ± 4 μM and flow-mediated vasodilation was 5±1%(SE). After therapy, trough serum arginine level increased to 43 ± 4 μM (p < 0.0005). Concomitant with this increase, flow-mediated vasodilation improved to 17±2% (p<.0001). Nitroglycerin-mediated vasodilation also increased (19±2% before, 24±2% after, p<.05). The effects of 2 bars/day was equal to that of 3 bars/day. The effect of the intervention was greater in females than males and was independent of the degree of initial dysfunction. The intervention also lowered total serum cholesterol (269±32 before, 253±41 after, p<.05). Other lipid values as well as serum chemistries and hematology were unaffected except for a decline in uric acid levels (5.0±2mg/dl before, 4.3±2 after p<.0001) and a rise in blood urea nitrogen (15±1mg/dl before, 19±1 after). The bars were well tolerated and no significant adverse side-effects were reported. Conclusion: This study demonstrates that 2 or 3 bars/day of this nutritional therapy can reverse endothelial dysfunction in individuals with hypercholesterolemia. This intervention may have an important role in the dietary management of individuals with hypercholesterolemia.