School of Sport, Exercise and Nutrition, Massey University, Auckland 0632, New Zealand.
School of Health Sciences, Massey University, Auckland 0632, New Zealand.
Nutrients. 2019 Jul 22;11(7):1683. doi: 10.3390/nu11071683.
Nitrate-rich beetroot juice supplementation has been shown to improve cardiovascular and cognitive function in younger and older adults via increased nitric oxide production. However, it is unclear whether the level of effects differs between the two groups. We hypothesized that acute supplementation with nitrate-rich beetroot juice would improve cardiovascular and cognitive function in older and younger adults, with the potential for greater improvements in older adults. Thirteen younger (18-30 years) and 11 older (50-70 years) adults consumed either 150 mL of nitrate-rich beetroot juice (BR; 10.5 mmol nitrate) or placebo (PL; 1 mmol nitrate) in a double-blind, crossover design, 2.25 h prior to a 30-min treadmill walk. Plasma nitrate and nitrite concentrations, blood pressure (BP), heart rate (HR), cognitive function, mood and perceptual tests were performed throughout the trial. BR consumption significantly increased plasma nitrate ( < 0.001) and nitrite ( = 0.003) concentrations and reduced systolic BP ( < 0.001) in both age groups and reduced diastolic BP ( = 0.013) in older adults. Older adults showed a greater elevation in plasma nitrite ( = 0.038) and a greater reduction in diastolic BP ( = 0.005) following BR consumption than younger adults. Reaction time was improved in the Stroop test following BR supplementation for both groups ( = 0.045). Acute BR supplementation increased plasma nitrite concentrations and reduced diastolic BP to a greater degree in older adults; whilst systolic BP was reduced in both older and younger adults, suggesting nitrate-rich BR may improve cardiovascular health, particularly in older adults due to the greater benefits from reductions in diastolic BP.
富含硝酸盐的甜菜根汁补充剂已被证明通过增加一氧化氮的产生来改善年轻和老年成年人的心血管和认知功能。然而，尚不清楚两组之间的效果水平是否存在差异。我们假设富含硝酸盐的甜菜根汁的急性补充会改善年轻和老年成年人的心血管和认知功能，并且老年人的改善潜力更大。13 名年轻（18-30 岁）和 11 名老年（50-70 岁）成年人在双盲交叉设计中分别饮用 150 毫升富含硝酸盐的甜菜根汁（BR；10.5 mmol 硝酸盐）或安慰剂（PL；1 mmol 硝酸盐），在 30 分钟跑步机步行前 2.25 小时。在整个试验过程中进行了血浆硝酸盐和亚硝酸盐浓度、血压（BP）、心率（HR）、认知功能、情绪和感知测试。BR 消耗显著增加了两组的血浆硝酸盐（<0.001）和亚硝酸盐（=0.003）浓度，并降低了收缩压（<0.001），并降低了老年人的舒张压（=0.013）。与年轻成年人相比，老年成年人在 BR 消耗后表现出更高的血浆亚硝酸盐升高（=0.038）和舒张压降低（=0.005）。BR 补充后，两组的斯特鲁普测试中的反应时间均得到改善（=0.045）。BR 急性补充可更大程度地增加血浆亚硝酸盐浓度并降低老年成年人的舒张压；而收缩压在年轻和老年成年人中均降低，表明富含硝酸盐的 BR 可能改善心血管健康，尤其是在老年人中，因为舒张压降低的益处更大。
