| 摘要: | 研究目的：茶 (Camellia sinensis) 有多種功效成分，包含兒茶素 (Catechins) 、茶胺酸 (Theanine) 、咖啡因 (Caffeine) 等，被認為具有提升與改善認知功能表現之潛力。認知功能可以分為多個領域包含注意力 (Attention)、記憶 (Memory)、執行功能 (Executive function) 、語言功能 (Language) 、知覺動作功能 (Perceptual-motor function) 等。老化、壓力、心理疲勞、飲食等因素，都會造成成人認知功能的暫時或永久性的影響。臨床研究對於茶成分改善各認知功能領域的結果不一致，並且先前相關的統合分析大多針對觀察型研究進行統計，或針對長期介入綠茶的隨機對照試驗進行單一測驗分數的統合分析，樣本量有限，沒有針對各領域的影響進行統整性的分析。因此，本研究欲納入隨機對照試驗，探討單次及長期茶成分對於各認知功能領域之影響。研究材料與方法：收錄PubMed、Embase、Cochrane library、Web of Science等資料庫中探討茶對於成人認知功能影響的隨機對照試驗，以穩健變異數估計法處理文獻的多個效果量，以相關性隨機效應模型，分為單次與長期介入 (兩周以上)，對各認知功能領域之分數進行統合分析。結果：39篇文獻進行統合分析，發現長期茶成分介入對於認知表現並沒有顯著影響，然而觀察到在介入12週以上，含有較高劑量兒茶素之茶成分，及對於40到60歲之臨床前期成人之認知表現改善趨勢提升。單次介入含有大於 15毫克之茶胺酸，及40到150毫克咖啡因之茶飲料，可以顯著提升注意力 (g = 0.27, [0.07, 0.47]; P = 0.008)、執行功能 (g = 0.17; [0.05, 0.29]; P = 0.009)、記憶 (g = 0.21; [0.04, 0.38]; P = 0.019)、語言功能 (g = 0.25; [0.11, 0.39]; P=0.004)，然而兒茶素之劑量與單次介入之效果並無顯著關聯性，同時對於18到40歲之成人之效果最佳。結論：單次攝取含有至少15毫克茶胺酸及40到150毫克咖啡因之茶飲品之後30至180分鐘內，可以顯著提升18歲以上成人之注意力、記憶、執行功能、語言認知功能表現，並且對於18歲以上40歲以下之健康男女效果最佳。然而持續長期攝取茶成分，對於認知功能各領域表現並無顯著提升之效果。
Objectives: Tea (Camellia sinensis) contains several bioactive components, including catechins, theanine, and caffeine, which are believed to enhance and improve cognitive function. Cognitive function can be divided into several domains, including attention, memory, executive function, language, and perceptual-motor function. Aging, stress, mental fatigue, and diet can cause temporary or permanent effects on cognitive function in adults. Previous research on the effects of tea components on various cognitive domains had yielded inconsistent results. Most prior meta-analyses focused on observational studies or single test scores from long-term green tea interventions in randomized controlled trials, with limited sample sizes and no comprehensive analysis of different cognitive domains. Therefore, this study aimed to include randomized controlled trials to investigate the single-dose and long-term effects of tea components on various cognitive domains. Materials and Methods: Randomized controlled trials investigating the effects of tea on cognitive function in adults were collected from databases such as PubMed, Embase, Cochrane Library, and Web of Science. Multiple effect sizes were handled using the robust variance estimation method and correlated random effects model was used to conduct meta-analyses on scores in different cognitive domains, categorized into single and long-term interventions (over two weeks). Results: A total of 39 studies were included in the meta-analysis. Long-term intervention with tea components showed a trend towards improvement in overall cognitive function and various domains, although not significant. However, it was observed that interventions lasting more than 12 weeks with high doses of catechins showed a trend of improved cognitive performance in preclinical adults aged 40 to 60 years. Single-dose tea beverages containing more than 15 mg of theanine and 40-150 mg of caffeine significantly improved attention (g=0.27, [0.07, 0.47]; P = 0.008), executive function (g = 0.17; [0.05, 0.29]; P = 0.009), memory (g = 0.21; [0.04, 0.38]; P = 0.019), and language cognition (g=0.25; [0.11, 0.39]; P=0.004). However, there was no significant correlation between catechins dosage and the effects of single interventions. The beneficial effects were most notable in adults aged 18 to 40 years old. Conclusion: Within 30 to 180 minutes after a single intake of tea beverages containing at least 15 mg of theanine and 40 to 150 mg of caffeine, the attention, memory, executive function, and language cognition performance of adults aged 18 and above can be significantly improved, with the best effects observed in healthy men and women aged 18 to 40 years. However, long-term consumption of tea components does not significantly enhance performance in various cognitive domains. |
