绿茶真的有益健康吗?

It's a drink which has become synonymous with a healthy lifestyle - but is green tea the magical potion many health sites would have us believe? Green tea has been popular in China for centuries, and has been used in traditional Chinese medicine to treat a number of health issues - including depression.
这一饮料已成为健康生活方式的代名词--但绿茶真的是魔法药水吗（很多健康网站希望我们这样认为）？绿茶已在中国流行了好几个世纪，也被用于中药治疗一系列健康问题--包括抑郁。

Its virtues have also been extolled by celebrities and so-called health experts for a number of reasons. These include its ability to help weight-loss, as well as containing antioxidants which are believed to help combat different types of cancer, heart disease and Alzheimer's. Given these claims, it's easy to see green tea as sort of magical elixir.
由于多种原因，绿茶的好处也得到了名人和所谓的健康专家的赞美。原因包括：其有助于减肥的能力、同时含有有助于抵抗多种癌症、心脏病和阿尔兹海默症的抗氧化剂。鉴于这些说法，绿茶很容易被视作神奇的灵药。

1. Green tea and weight loss
1. 绿茶和减肥

Green tea contains B vitamins, folate (naturally occurring folic acid), manganese, potassium, magnesium, caffeine and other antioxidants, such as catechins. It's catechins - along with green tea's naturally occurring caffeine - which are thought to help the body burn more calories.
绿茶含有B族维生素、叶酸（天然存在的叶酸）、镁元素、咖啡因和其它抗氧化物，如儿茶素。人们认为绿茶的儿茶素和其天然含有的咖啡因有助于人体燃烧更多的卡路里。

Weight-loss products containing green tea have a higher concentration of catechins and caffeine than the typical green tea beverage. However, there's some bad news. A review from 2012 of 18 studies involving 1,945 people found no significant effect of weight loss from drinking green tea.
含有绿茶的减肥产品比典型的绿茶饮料含有更高的儿茶素和咖啡因浓度。然而坏消息是，2012至2018年间开展的涉及1945人的综述发现：喝绿茶并没有显著的减肥效果。

2. Green tea and cholesterol
2. 绿茶和胆固醇

Thanks again to the catechins, in a reputable review from 2013 of 11 studies involving 821 people, it was found daily consumption of green and black tea (as a drink or a capsule) could help lower cholesterol and blood pressure.
再次感谢儿茶素，2013年对11项涉及821人的有声誉的综述发现：每天喝绿茶和红茶（饮料或者胶囊）有助于降低胆固醇和高血压。

It's important to note, however, that the authors of the study pointed out the trials were short-term, and cautioned longer-term trials would be needed to substantiate their findings. These were back up by an earlier review in 2011, which found drinking green tea enriched with catechins led to a small reduction in cholesterol, a main cause of heart disease and stroke.
然而，值得注意的是，研究的作者指出：试验是短期的，并警告称需要长期试验来证实他们的发现。2011年的一份综述支持这一观点，发现富含儿茶素的饮用绿茶会导致胆固醇略微降低，胆固醇是导致心脏病和中风的主要原因。

Though no one could say for certain how much green tea a person would need to drink to reap the benefits.
尽管没有人能够确定需要喝多少的绿茶才能获得这个好处。

3. Green tea and cancer
3. 绿茶和癌症

On this the NHS is clear. There is no evidence drinking green tea protects against different types of cancer.
英国国民健康体系对此十分清楚。没有证据证明喝绿茶能够抵抗不同类型的癌症。