Centre for Academic Primary Care, NIHR School for Primary Care Research, School of Social and Community Medicine, University of Bristol, Bristol, United Kingdom.
Maturitas. 2012 Dec;73(4):280-7. doi: 10.1016/j.maturitas.2012.08.008. Epub 2012 Sep 15.
Tea leaves contain varying amounts of polyphenols of which the majority are catechins. There has been a sizable amount of research on the potential effect of green tea catechins for cancer risk, cardiovascular disease risk and weight loss; all conditions that are relevant to mid-life health. The aim was to produce an overview of the evidence for green tea for these three important health conditions.
The databases Medline (& Medline in process) and Embase, were searched for systematic reviews and meta-analyses using customised search strategies performed up until April 2012. Assessment of Multiple Systematic Reviews criteria were used to assess the quality of the included reviews. Relevant data were extracted into predefined tables. The results are described and discussed narratively.
We included eight systematic reviews and meta-analyses covering the topics of cancer risk (n=2), cardiovascular risk (n=4) and weight loss (n=2).
The evidence for green tea and cancer risk is inadequate and inconclusive. However there is some positive evidence for risk reduction of breast, prostate, ovarian and endometrial cancers with green tea. RCTs of green tea and cardiovascular risk factors suggest that green tea may reduce low-density lipoproteins and total cholesterol, although studies are of short duration. There is no robust evidence to support a reduction in coronary artery disease risk in green tea drinkers. There are a considerable number of RCTs to suggest that green tea does reduce body weight in the short term, but this not likely to be of clinical relevance.
茶叶含有不同含量的多酚，其中大部分是儿茶素。已经有相当数量的研究表明，绿茶儿茶素有降低癌症风险、心血管疾病风险和减肥的潜力；所有这些条件都与中年健康有关。本研究旨在综述绿茶在这三种重要健康状况下的证据。
使用定制的搜索策略在 Medline（& Medline in process）和 Embase 数据库中搜索系统评价和荟萃分析，检索时间截至 2012 年 4 月。使用多个系统评价评估标准来评估纳入评价的质量。将相关数据提取到预定义的表格中。结果以叙述的方式进行描述和讨论。
我们纳入了 8 篇系统评价和荟萃分析，涵盖了癌症风险（n=2）、心血管风险（n=4）和减肥（n=2）等主题。
绿茶与癌症风险的证据不足且不明确。然而，绿茶可能降低乳腺癌、前列腺癌、卵巢癌和子宫内膜癌的风险，这方面有一些积极的证据。绿茶与心血管风险因素的 RCT 表明，绿茶可能降低低密度脂蛋白和总胆固醇，但研究持续时间较短。没有确凿的证据支持绿茶能降低冠心病风险。有相当数量的 RCT 表明，绿茶在短期内确实能减轻体重，但这可能不具有临床意义。
