Hot tea can increase the risk of a deadly cancer five-fold for people who also regularly drink alcohol, Chinese research suggests.
People who drink at least one alcoholic beverage and a “burning hot” cup of tea on a daily basis were five times more likely to develop esophageal cancer than people who drank tea at any temperature less than once a week, the study found.
Esophageal cancer is the eighth most common cancer in the world and is often fatal, killing approximately 400,000 people every year, according to the International Agency for Research on Cancer.
It is usually caused by repeated injury to the esophagus due to smoke, alcohol, acid reflux and — maybe — hot liquids.
The risks to smokers also increase with high-temperature tea drinking, said the study, which examined data on 456,155 Chinese adults ages 30 to 79.
Drinking boiling hot tea every day was associated with roughly twice the risk of oesophageal cancer as consuming tea less than weekly for people who smoked.
Both smoking and drinking alcohol are already widely-known to be linked to oesophageal cancer, but the new study, which appeared in the Annals of Internal Medicine, proved that very hot tea can increase the risks.
Lv Jun, of Peking University Health Science Centre in China, who co-authored the study, said: “Boiling hot tea will harm the cells in the oesophagus. “If the person also drinks alcohol and smokes, then the harm caused will be more heightened.”
At the start of the study, none of the participants had cancer. Researchers followed half of the participants for at least nine years.
During the study, 1,731 people developed oesophageal tumours.
Each year, oesophageal cancer – which killed Inspector Morse actor John Thaw – is diagnosed in around 9,000 people in the UK, and an estimated 15 per cent of patients who develop the cancer are still alive after five years.
Rates of the disease are relatively high in China, where tea drinking is common and many men smoke and drink.
Chinese people often drink tea from flasks that they carry with them to their workplace and regularly fill up with hot water.
Very few Chinese drink traditional British tea, which less hot than Chinese varieties as it also usually taken with cold milk.
Cancer | The tests you need to know about
For bile duct cancer
Helen Moremont, of the charity AMMF, says if you have symptoms of bile duct cancer that don’t improve, ask your GP to run a liver-function test.
For ovarian cancer
An early ovarian cancer-screening tool is in development. ‘In the meantime, if you have symptoms for longer than a 12-day period, ask your GP for a CA125 blood test,’ says Katherine Taylor of Ovarian Cancer Action. ‘It’s a bio-marker test that’s freely available.’
For cervical cancer
Since the early 1990s, cervical cancer incidence rates have decreased by almost a quarter (23 per cent) in the UK. Women aged 25 to 49 are invited for screening every three years; 50 to 64-year-olds are invited every five years. If you experience bleeding between periods, after sex or following the menopause, or have pain during sex or in your pelvis, see your GP.
For bowel cancer
If bowel cancer is detected early, before symptoms appear, it is easier to treat. The NHS offers two types of bowel-cancer screening. Currently, everybody aged 60 to 74 is sent a home- test kit. There is also a one-off test called bowel scope screening (which takes place at NHS bowel-cancer screening centres), which is gradually being introduced in England for those 55 and over.
Don’t forget the protective basics: ‘Four in 10 cases of cancer can be prevented. So if you’re a smoker, stop; keep a healthy weight; eat well and stay active,’ says Dr Jasmine Just of Cancer Research UK. ‘Help stack the odds in your favour.’
People in Russia, Turkey and South America enjoy their tea very hot, with many regularly drinking it at temperatures above 149 degrees Fahrenheit (65 degrees Celsius).
Past research has shown that tea can help to protect against tumours in the digestive tract.
But studies have also suggested that hot liquids and food can cause “thermal injury” which can increase the risk factors associated with cancer.