The World Health Organisation advises we wait for our morning cup of English breakfast to cool slightly to decrease the risk of getting cancer of the oesophagus. But just how hot is too hot?

世界卫生组织建议，喝茶的时候等水凉一凉，可以降低患上食道癌的风险。但到底多热是太热?

Until now, most research has been rather vague on the actual temperature part. After all, what is scalding to one person might be another's perfect brew. At last we have a number to help you decide when to take your first sip.

到目前为止，大多数研究具体的温度部分都比较模糊。毕竟，每个人对烫的具体感受都有所不同。我们这里倒是有一个数字供您参考。

An international team of researchers have come together to objectively nail down a Goldilocks temperature for drinkers of hot beverages, and found that once the drinking liquid creeps past 60 degrees Celsius (140 degrees Fahrenheit), you're taking your chances.

曾有一支国际团队希望确定热饮适宜入口时的客观温度，然后发现60℃很合适。

To give you a sense of what that feels like, most of us will start to experience discomfort when we touch a surface that's approaching 50 degrees Celsius. So unless you're something of a masochist when it comes to that first mouthful, the news isn't all that bad.

Emmmm。如果你喜欢喝茶的同时体验受虐式的口腔刺激，那不妨一试。

"Many people enjoy drinking tea, coffee, or other hot beverages," says Farhad Islami from the American Cancer Society.

“许多人喜欢喝茶，咖啡或其他热饮，”美国癌症协会的Farhad Islami说，

"However, according to our report, drinking very hot tea can increase the risk of oesophageal cancer, and it is therefore advisable to wait until hot beverages cool down before drinking."

“然而，根据我们的报告，饮用非常热的茶会增加食道癌的风险，因此建议等热饮料冷却后再饮用。”

There's plenty of research telling us the temperature of our drinks can affect our chances of developing cancer. Exactly how it does this isn't clear, but the evidence suggests damage caused by blanching our throat's cells is probably responsible.

有大量的研究支持上面的结论。不过我们尚不清楚热饮引发食道癌的机理，但证据表明，喉咙细胞被烫伤时造成的损害可能是致癌元凶。

Most studies on the topic focus on the more popular habit of tea drinking, asking participants to comment on how they prefer their water.

关于该主题的大多数研究都集中在更受欢迎的饮茶习惯上，还需要参与者上报自己的水温偏好。

It might be a quick and easy way to collect data, but few people are likely to offer precise figures. So advisory groups such as the WHO's International Agency for Research on Cancer lean on animal studies that suggest 65 degrees Celsius is a suitable cut-off limit.

这可能是一种快速简便的数据采集方式，但很少有人能够提供准确的数据。因此，世界卫生组织国际癌症研究机构等团队利用动物实验，发现65℃是一个合适的临界值——当然这很烫。

To improve on previous studies, researchers initiated an investigation in Golestan Province, northeast of Iran – an area already subjected to scientific scrutiny for both its culture of tea drinking and its relatively high incidence of oesophageal cancer.

为了改进实验，研究人员在伊朗东北部的Golestan省开展了一项调查——该地区以其饮茶习俗和相对较高的食道癌发病率而闻名癌症研究界。

An added bonus was the low incidence of smoking and alcohol drinking, habits which could have affected results.

当地，另有一个好处是，当地吸烟和饮酒的人群很少，这些不良习惯可能会带来误差。

Starting in 2004, trained data collectors gathered information on more than 50,000 participants, recording details on everything from their smoking habits to their socioeconomic status to how long they tended to wait before drinking their tea. They were then followed up over the years with phone calls, checking in on their health.

从2004年开始，训练有素的数据采集人员收集到了超过50000名参与者的医疗—生活信息，从吸烟习惯到社会经济状况，乃至喝茶前他们要晾多久的所有细节。多年来，他们通过电话跟进，追踪目标人群的健康状况。

Most importantly, the team served tea during the initial interview calibrated to a piping hot 75 degrees. Guests were then invited to take a sip and comment whether it felt close to the temperature they preferred.

最重要的是，该团队在初次面试时，进行了面对面的茶水热度实验，提供了75℃的热茶，然后邀请客人啜饮并评论。如果有客人感觉太热，团队就等水温降低5℃后再次邀请客人品尝。

For those who liked it a little cooler, the team let the water's temperature fall another five degrees before asking again.

如果还是觉得烫嘴，就继续降低5℃，以此类推。

The end results sound a little concerning. Those who drink less than 700 millilitres of tea (roughly two mugs worth) heated to more than 60 degrees Celsius nearly doubled their risk of developing cancer of the oesophagus compared with 'cooler' drinkers.

结果有点令人担忧。那些习惯日饮用700毫升60℃以上热茶的人，患上食道癌的风险比其他人群几乎翻了一番。

Of course, we need to put those numbers into perspective. This form of cancer ranks around number eight in most common cancers, with a lifetime risk for those in the US of around 1 in 132 men and 1 in 455 women.

当然，我们需要对这些数字进行分析。这种形式的癌症在大多数常见癌症中排名第八，对于美国人来说，每132名男性和455名女性中，就有1人罹患食道癌。

For those in other parts of the world, such as Iran and China, it's a far more common disease, with other contributory factors to do with diet and smoking affecting incidence rates.

对于世界其他地区，例如伊朗和中国，这是一种更常见的癌症，致病因素与饮食和吸烟有关。

Before you ditch the kettle, it helps to keep in mind drinking tea – especially of the green variety – just might help lower risks of a variety of cancers.

不要因此拒绝喝茶——尤其是绿茶——研究发现它们有助于降低各种癌症的风险。

Evidence is mixed, but having a few cups of unsweetened tea a day probably isn't going to do much harm.

虽然证据不一，但每天喝几杯不加糖的茶反正也不会造成太大的伤害。

Just make sure you hold off for a few minutes to let it cool first.

只要你耐住性子，等它凉了。

This research was published in the International Journal of Cancer.

该研究发表在《国际癌症期刊》上。