WHO study says too hot drinks can cause cancer. Photo: Li Hao/GT

"When I said 'in the morling' in my first demonstration class, the students and parents burst into laughter," recalled Meng Jie, a 23-year-old primary school English teacher in Nanjing, Jiangsu Province.

Her constant mispronunciation of the word morning, has Meng worried that her childhood habit of drinking hot drinks might be harming her throat and speech.

"If my drinks get too cold, I will lose interest," said Meng, whose more than a decade-long habit has her mouth or tongue always blistered from drinking hot tea, soup, and water.

Despite the blisters and burns, Meng never once considered giving up her love for hot drinks. Even in the summer, she insists drinking hot water and tea because she thinks hot beverages are better for one's health.

China has a long tradition of drinking hot beverages, especially hot water and tea. According to a March 12 Los Angeles Times report, for many Westerners, drinking hot water is odd, but most Chinese think chugging ice water is equally bizarre and unhealthy, even in the summer.

However, drinking too hot beverages may not be that healthy. According to a study by the International Agency for Research on Cancer (IARC) under the World Health Organization (WHO) published in the Lancet Oncology journal - a monthly medical journal known for its high-quality, peer-reviewed research - on June 15, consuming over hot drinks has been linked to ailments.

The research revealed the potential carcinogenicity of drinking coffee, maté (a tealike beverage drunk especially in South America), and very hot beverages. It suggested that very hot beverages could cause esophageal cancer.

According to the findings, people in China, Turkey, and South American countries have a higher risk of esophageal cancer because of their tradition of drinking beverages with temperatures of about 70 C.

According to Zheng Yulong, the president of Zheng Yulong Nutrition Center and a nutritionist in Qingdao, Shandong Province, the mucosa in the mouth, esophagus and stomach is extremely delicate and super hot drinks can burn the mucosa and cause lesions, which could lead to cancer if the mucosa is repeatedly damaged.

To protect the upper digestive system, Zheng suggested that people eat food at a temperature which does not harm their mouths.

"The normal temperature inside the mouth is 35 to 36 C, and people will feel a stabbing pain when eating things over 60 C," said Zheng.

Less horrifying than cancer, there are other discomforts that can result from drinking very hot drinks.

Zheng said the upper digestive system uses digestive juices including the digestive enzymes in the mouth and stomach. He said hot food and drinks directly affect these digestive juices because they deactivate the enzymes and reduce the production of stomach juices. 

"So avoid drinking too hot beverages before meals to protect your ability to digest," he said.

Zheng further suggested that people who want to lose weight or keep fit should also be careful about the amount of hot drinks they consume.

"The high temperature can 'trick' people's sense of taste and make sweet drinks taste less sweet," he said.

Sweet drinks usually contain high amounts of fructose, which is a kind of sugar that exists in beverages like fruit juices. It tastes sweeter at low temperatures. That is why many people are likely to add more sugar when drinking hot beverages.

According to Zheng, the optimum temperature for food and drink is about 50 C, which is neither too hot nor too cold.

Meanwhile, Meng has decided to go to the hospital to check her mouth. "Although it is hard to quit drinking hot stuff, I will try," she said.