Faculty of Liberal Arts and Sciences, Chukyo University, Aichi, Japan.
Faculty of Sport and Health Science, Ritsumeikan University, Shiga, Japan.
J Appl Physiol (1985). 2022 Jul 1;133(1):69-74. doi: 10.1152/japplphysiol.00200.2022. Epub 2022 Jun 2.
Nutritional strategies to prevent endothelial dysfunction following prolonged sitting remain largely unknown. Given that beetroot juice (BRJ) ingestion enhances nitric oxide (NO) bioavailability, we aimed to evaluate whether prior BRJ ingestion would prevent sitting-induced endothelial dysfunction in the leg. Eleven healthy young males ( = 7) and females ( = 4) underwent two experimental trials of prolonged sitting with prior: ) placebo (PL) ingestion (PL trial) and ) BRJ ingestion (BRJ trial). All subjects ingested 140 mL of PL or BRJ (∼0.0055 or ∼12.8 mmol of nitrate, respectively) immediately before 3 h of sitting. Pre- and post-sitting measurements of popliteal artery flow-mediated dilation (FMD) and blood pressure, and blood collection were undertaken. During the sitting period, an hourly assessment of popliteal artery diameter and blood velocity, blood pressure, and blood collection were performed. Popliteal artery blood flow and shear rate were significantly and similarly reduced during the sitting period in both trials ( < 0.001). Plasma nitrate and NOx (total nitrite and nitrate) concentrations were significantly increased relative to baseline in the only BRJ trial, and the overall concentrations were significantly higher in the BRJ trial ( < 0.001). Popliteal artery FMD was significantly reduced after the sitting period in the PL trial ( < 0.05), whereas no reduction was observed in the BRJ trial. Therefore, prior BRJ ingestion would prevent sitting-induced leg endothelial dysfunction via enhancing NO bioavailability. The present study elucidates that beetroot juice ingestion before prolonged sitting offsets sitting-induced leg endothelial dysfunction. Data from the present study provides novel physiological information that enhancing NO bioavailability by dietary nitrate supplementation is an effective tool for prevention of the detrimental vascular effects of prolonged sitting.
关于预防长时间久坐后内皮功能障碍的营养策略在很大程度上仍然未知。鉴于甜菜根汁（BRJ）的摄入可以增强一氧化氮（NO）的生物利用度，我们旨在评估在久坐之前摄入 BRJ 是否可以预防腿部的久坐引起的内皮功能障碍。11 名健康的年轻男性（= 7）和女性（= 4）分别进行了两次长时间久坐的实验，分别是：）安慰剂（PL）摄入（PL 试验）和）BRJ 摄入（BRJ 试验）。所有受试者在久坐前 3 小时内立即摄入 140 毫升 PL 或 BRJ（分别约为 0.0055 或 12.8mmol 的硝酸盐）。在久坐前后测量腘动脉血流介导的扩张（FMD）和血压，并进行血液采集。在久坐期间，每小时评估腘动脉直径和血流速度、血压和血液采集。在两次试验中，腘动脉血流和剪切率在久坐期间均显著且相似地降低（<0.001）。仅在 BRJ 试验中，血浆硝酸盐和 NOx（总亚硝酸盐和硝酸盐）浓度相对于基线显著增加，并且 BRJ 试验中的总体浓度显著更高（<0.001）。在 PL 试验中，久坐后腘动脉 FMD 显著降低（<0.05），而在 BRJ 试验中未观察到降低。因此，BRJ 摄入前可通过增强 NO 生物利用度来预防久坐引起的腿部内皮功能障碍。本研究阐明了在长时间久坐之前摄入 BRJ 可以抵消久坐引起的腿部内皮功能障碍。本研究的数据提供了新的生理信息，即通过膳食硝酸盐补充增强 NO 生物利用度是预防长时间久坐对血管有害影响的有效工具。
