Health & Wellness Products Research Laboratories, Kao Corporation, Tokyo 131-8501, Japan.
Biological Science Research Laboratories, Kao Corporation, Tokyo 131-8501, Japan.
Nutrients. 2022 Apr 29;14(9):1856. doi: 10.3390/nu14091856.
Tea catechins are plant-derived compounds that improve immune functions. Previous randomized control trials have demonstrated the efficacy of primarily epi-type catechins against upper respiratory tract infections (URTIs). Green tea can be consumed in several ways, including popular bottled beverages. These beverages, however, require sterilization during manufacturing, which results in catechin isomerization. We conducted a randomized, double-blinded, placebo-controlled trial involving healthy Japanese participants to evaluate whether catechin consumption via bottled beverages has an alleviating effect on the duration and severity of URTIs in winter. The catechin group (490 mg catechin, 0.14%, containing 59% epi-type catechin, n = 55) showed reduced durations of running nose, nasal congestion, and headache, compared with the placebo group (0 mg catechin, n = 54; p = 0.013, 0.018, and <0.001, respectively). Furthermore, when considering physical symptoms, the duration of nasopharyngeal symptoms improved significantly in the catechin group (p < 0.001) compared with that in the control group. The daily consumption of catechin thus reduced the duration and severity of URTIs in healthy men and women. Humans are regularly exposed to several potential infectious threats, and the oral administration of heat-epimerized tea catechins might help prevent and reduce the severity of URTIs.
茶儿茶素是植物衍生的化合物，可改善免疫功能。先前的随机对照试验已经证明了主要表儿茶素对上呼吸道感染（URTIs）的疗效。绿茶可以通过多种方式食用，包括流行的瓶装饮料。然而，这些饮料在制造过程中需要经过灭菌处理，这会导致儿茶素异构化。我们进行了一项随机、双盲、安慰剂对照试验，涉及健康的日本参与者，以评估通过瓶装饮料摄入儿茶素是否对冬季 URTIs 的持续时间和严重程度有缓解作用。儿茶素组（490mg 儿茶素，0.14%，含 59%表儿茶素，n=55）与安慰剂组（0mg 儿茶素，n=54）相比，流鼻涕、鼻塞和头痛的持续时间缩短（p=0.013，0.018 和<0.001）。此外，考虑到身体症状，儿茶素组的鼻咽症状持续时间明显改善（p<0.001），而对照组无明显改善。因此，每日摄入儿茶素可缩短健康男性和女性 URTIs 的持续时间和严重程度。人类经常面临多种潜在的感染威胁，口服热异构化茶儿茶素可能有助于预防和减轻 URTIs 的严重程度。
