Ma Qing-Ping, Huang Chen, Cui Qiao-Yun, Yang Ding-Jun, Sun Kang, Chen Xuan, Li Xing-Hui
Tea Research Institute, College of Horticulture, Nanjing Agricultural University, Nanjing, Jiangsu Province, China.
PLoS One. 2016 Nov 8;11(11):e0165861. doi: 10.1371/journal.pone.0165861. eCollection 2016.
Alzheimer's disease is a common neurodegenerative disorder in elderly. This study was aimed to systematically evaluate the association between tea intake and the risk of cognitive disorders by meta-analysis.
PubMed, Embase and Wanfang databases were systematically searched and a total of 26 observational studies were included in this study. Odds ratios (ORs) and the corresponding 95% confidence intervals (CIs) were calculated and pooled by using fixed or random effects models according to the degree of heterogeneity.
The overall pooled analysis indicated that tea intake could significantly reduce the risk of cognitive disorders (OR = 0.65, 95%CI = 0.58-0.73). Subgroup analyses were conducted based on study design, population, frequency of tea drinking and type of cognitive disorders. The results showed that tea drinking was significantly associated with the reduced incidence of cognitive disorders in all of subgroups based on study design and frequency of tea drinking. In particular, tea drinking was inversely associated with the risk of cognitive impairment (CoI), mild cognitive impairment (MCI), cognitive decline and ungrouped cognitive disorders. Moreover, for population subgroups, the significant association was only found in Chinese people.
Our study suggests that daily tea drinking is associated with decreased risk of CoI, MCI and cognitive decline in the elderly. However, the association between tea intake and Alzheimer's disease remains elusive.
阿尔茨海默病是老年人常见的神经退行性疾病。本研究旨在通过荟萃分析系统评价饮茶与认知障碍风险之间的关联。
系统检索了PubMed、Embase和万方数据库，共纳入26项观察性研究。根据异质性程度，采用固定效应模型或随机效应模型计算并汇总比值比（OR）及相应的95%置信区间（CI）。
总体汇总分析表明，饮茶可显著降低认知障碍风险（OR = 0.65，95%CI = 0.58 - 0.73）。根据研究设计、人群、饮茶频率和认知障碍类型进行亚组分析。结果显示，基于研究设计和饮茶频率的所有亚组中，饮茶均与认知障碍发病率降低显著相关。特别是，饮茶与认知损害（CoI）、轻度认知障碍（MCI）、认知衰退和未分组认知障碍的风险呈负相关。此外，在人群亚组中，仅在中国人群中发现了显著关联。
我们的研究表明，日常饮茶与老年人CoI、MCI和认知衰退风险降低有关。然而，饮茶与阿尔茨海默病之间的关联仍不明确。
