Data from; Concentration-Dependent Impact of Green Tea Catechin Gargling on Acute Upper Respiratory Tract Infections: An Exploratory Randomized Controlled Trial

We conducted an open-label randomized study (UMIN000045060). The target population consisted of 209 students from the University of Shizuoka and Meiji University, who were randomly assigned to high-catechin (70 participants, approximate catechin concentration: 76.4 mg/dL), low-catechin (69 participants, approximate catechin concentration: 30.8 mg/dL), and a control water gargling (70 participants, catechin concentration: 0 mg/dL) groups. All participants gargled water or GT thrice daily for 12 weeks between December 2021 and February 2022. The symptoms experienced by participants who developed URTI during the study period were recorded on a survey form. The primary endpoint of URTI occurred in 6 (9.1%), 7 (10.8%), and 11 (15.7%) participants in the high-catechin, low-catechin, and water groups, respectively (Fisher's exact test for the overall group: <em>p</em>=0.482). Cox proportional hazards analysis, using background factors and prevention status as covariates, revealed a hazard ratio of 0.57 (95% CI: 0.21–1.55, <em>p</em>=0.261) for the high-catechin vs. water group and 0.54 (95% CI: 0.20–1.50, <em>p</em>=0.341) for the low-catechin vs. water group.我们开展了一项开放标签随机研究（UMIN000045060）。研究对象为静冈大学与明治大学的209名学生，按随机分组分为高儿茶素组（70名受试者，儿茶素近似浓度：76.4 mg/dL）、低儿茶素组（69名受试者，儿茶素近似浓度：30.8 mg/dL）以及对照漱口组（70名受试者，儿茶素浓度：0 mg/dL）。所有受试者于2021年12月至2022年2月期间，每日以清水或GT漱口3次，持续12周。研究期间出现上呼吸道感染（Upper Respiratory Tract Infection, URTI）的受试者，其相关症状均通过调查问卷记录。高儿茶素组、低儿茶素组与清水对照组中，出现URTI的受试者分别为6例（9.1%）、7例（10.8%）与11例（15.7%）；整体组间比较采用Fisher精确检验，*p*=0.482。以基线背景因素与干预状态为协变量开展Cox比例风险分析，结果显示：高儿茶素组相较清水对照组的风险比为0.57（95%置信区间：0.21–1.55，*p*=0.261），低儿茶素组相较清水对照组的风险比为0.54（95%置信区间：0.20–1.50，*p*=0.341）。