Acute dietary nitrate supplementation significantly improved superficial femoral artery flow mediated dilatation compared to placebo (+1.18% vs. 0.23%, p=0.002) in healthy older men.
RCT (n=15)
Double-blind
Randomized cross-over
Does acute dietary nitrate supplementation improve flow mediated dilatation and passive leg movement hyperaemia in healthy older men?
Acute dietary nitrate supplementation improves endothelial function and reduces arterial stiffness in healthy older men.
Absolute Event Rate: 1.18% vs 0.23%
p-value: p=0.002
Aging is often associated with reduced leg blood flow, increased arterial stiffness, and endothelial dysfunction, all of which are related to declining nitric oxide (NO) bioavailability. Flow mediated dilatation (FMD) and passive leg movement (PLM) hyperaemia are two techniques used to measure NO-dependent vascular function. We hypothesised that acute dietary nitrate (NO3−) supplementation would improve NO bioavailability, leg FMD, and PLM hyperaemia. Fifteen healthy older men (69 ± 4 years) attended two experiment sessions and consumed either 140 mL of concentrated beetroot juice (800 mg NO3−) or placebo (NO3−-depleted beetroot juice) in a randomised, double blind, cross-over design study. Plasma nitrite (NO2−) and NO3−, blood pressure (BP), augmentation index (AIx75), pulse wave velocity (PWV), FMD of the superficial femoral artery, and PLM hyperaemia were measured immediately before and 2.5 h after consuming NO3− and placebo. Placebo had no effect but NO3− led to an 8.6-fold increase in plasma NO2−, which was accompanied by an increase in FMD (NO3−: +1.18 ± 0.94% vs. placebo: 0.23 ± 1.13%, p = 0.002), and a reduction in AIx75 (NO3−: −8.7 ± 11.6% vs. placebo: −4.6 ± 5.5%, p = 0.027). PLM hyperaemia, BP, and PWV were unchanged during both trials. This study showed that a dose of dietary NO3− improved NO bioavailability and enhanced endothelial function as measured by femoral artery FMD. These findings provide insight into the specific central and peripheral vascular responses to dietary NO3− supplementation in older adults.
Walker et al. (Fri,) conducted a rct in Healthy older men (n=15). Dietary nitrate (concentrated beetroot juice) vs. Placebo (NO3--depleted beetroot juice) was evaluated on Flow mediated dilatation (FMD) of the superficial femoral artery (p=0.002). Acute dietary nitrate supplementation significantly improved superficial femoral artery flow mediated dilatation compared to placebo (+1.18% vs. 0.23%, p=0.002) in healthy older men.