Moderate coffee drinking is safe, and three to four cups a day may have some health benefits, according to a large review of previous studies, in the BMJ.
根据《英国医学杂志》早先开展的一项大范围研究，适量饮用咖啡是安全的，每天喝三到四杯咖啡还对身体有益。

It found a lower risk of liver disease and some cancers, and a lower risk of dying from stroke - but researchers could not prove coffee was the cause.
研究发现，喝咖啡的人患上肝脏疾病、某些癌症和死于中风的风险更低，但他们不确定这与咖啡有关。

Too much coffee during pregnancy could be harmful, the review confirmed.
研究确认，孕妇喝咖啡太多对身体有害。

Experts said people should not start drinking coffee for health reasons or to prevent disease.
专家表示，人们不应该为了健康原因或者为了预防疾病而去喝咖啡。

The University of Southampton researchers collected data on the impact of coffee on all aspects of the human body, taking into account more than 200 studies - most of which were observational.
南安普顿大学的研究人员收集了咖啡对人身体所有方面影响的数据，考察了200多项研究，大部分是观察性研究。

Was it the coffee?
是因为咖啡吗？

Compared with non-coffee drinkers, those who drank about three cups of coffee a day appeared to reduce their risk of getting heart problems or dying from them.
与不喝咖啡的人相比，每天喝大约三杯咖啡的人患上心脏病或死于心脏病的风险会降低。

The strongest benefits of coffee consumption were seen in reduced risks of liver disease, including cancer.
喝咖啡最大的健康益处是患肝脏疾病（包括肝癌）的风险降低。

But Prof Paul Roderick, co-author of the study, said the review could not say if coffee intake had made the difference.
但研究报告的合著者保罗-罗德里克教授说，研究结论无法证实这种差异是否由咖啡导致。

"Factors such as age, whether people smoked or not and how much exercise they took could all have had an effect," he said.
他说：“年龄、是否吸烟、每天做多少运动等因素都有影响。”

The findings back up other recent reviews and studies of coffee drinking so, overall, his message on coffee was reassuring.
这一研究结果支持了最近的其他几项有关喝咖啡作用的综述和研究，因此从总体上看，研究结果是可靠的。

"There is a balance of risks in life, and the benefits of moderate consumption of coffee seem to outweigh the risks," he said.
他说：“生活中各种风险之间存在平衡，适量饮用咖啡的益处看来比风险更大。”

The NHS recommends pregnant women have no more than 200mg of caffeine a day - two mugs of instant coffee - because too much can increase the risk of miscarriage.
英国国民健康保险体系建议孕妇每天摄入的咖啡因不超过200毫克，也就是两杯速溶咖啡的量，因为摄入咖啡因太多会增大流产风险。

This review suggests women at risk of fractures should also cut back on coffee.
研究建议有骨折风险的女性也要少喝咖啡。

For other adults, moderate caffeine intake equates to 400mg or less per day - or three to four cups.
对其他成年人来说，每天摄入的咖啡因最好少于400毫克，大约相当于三到四杯咖啡。

咖啡中有多少咖啡因？

one mug of instant coffee: 100mg
一杯速溶咖啡：100毫克

one mug of filter coffee: 140mg
一杯滤挂咖啡：140毫克

one mug of tea: 75mg
一杯茶：75毫克

one can of cola: 40mg
一罐可乐：40毫克

one 250ml can of energy drink: up to 80mg
一罐250毫升的能量饮料：最多80毫克

bar of plain chocolate: less than 25mg
一条纯巧克力：少于25毫克

bar of milk chocolate: less than 10mg
一条牛奶巧克力：少于10毫克

The researchers say coffee drinkers should stick to "healthy coffees" - which avoid extra sugar, milk or cream, or a fatty snack on the side.
研究人员表示，喝咖啡的人要坚持喝“健康咖啡”，不要另外加糖、牛奶、奶油，或者高脂肪零食。

And they are calling for rigorous clinical trials on coffee intake to find out more about the potential benefits to health.
研究人员提议对咖啡摄入量进行严格的临床试验，以对咖啡潜在的健康益处有更多了解。

At present, the researchers said pinning down exactly how coffee might have a positive impact on health was "difficult".
目前，研究人员表示精确指出咖啡如何有益健康“有些困难”。