可乐之中含有致癌物质?

类似可乐这样的“软”饮料，有它独特的魅力。许多人在吃完汉堡薯条或烧烤食物，满嘴油腻荤腥时，总是急着找可乐，狠狠灌上几口之后。 然而，在全球可乐销售历久不衰之际，专家却指出：这种饮料中所含让饮料变成棕色的成分，正是可怕的致癌物。

Cracking open a can of cola may not appear to be a dangerous activity. But scientists in the United States say there is "clear evidence" that chemicals used in these drinks could cause cancer. As a result, the US consumer group Center for Science in the Public Interest is calling for the ingredients to be banned. Jeff Cronin is from the organization. He says it's all about the caramel.

"Most people probably think of caramel as melted sugar that they can make at home on the stove. It turns out the sort of caramel colouring that's used by Coke and Pepsi is actually quite different. Food companies use ammonia and sulfites to make this caramel colour dye. And when ammonia is used it produces two carcinogens."

In response to the research, the American Beverage Association, which represents soft drinks manufacturers in the US, released the following statement about the chemical in question, commonly referred to as 4-MEI.

"4-MEI is not a threat to human health. There is no evidence that 4-MEI causes cancer in humans. No health regulatory agency around the globe, including the Food and Drug Administration, has said that 4-MEI is a human carcinogen."

Regardless of the debate about 4-MEI, the Center for Science in the Public Interest says a greater risk is the amount of sugar in soft drinks. Too much can cause obesity and other diseases such as diabetes. Professor Wu Yangfeng is from the George Institute for Global Health. He says it's a problem for China, too.

"…Now we have many more children developing type two diabetes. Previously this was very rare in China. There are more and more obese children nowadays in schools and also there are some other studies in China showing an association between beverage drinks and obesity in children."

But are people on the street worried about the health risks of sugary drinks? Consumers in this shopping mall don't seem too concerned.

"People say drinking cola is not healthy but they also say drinking a little is not so bad. I drink when I'm under pressure."

"I have many friends who like to drink this kind of soft drink very much. They drink very often, every day, every moment."

The World Health Organisation predicts the number of people with diabetes in China could reach half a billion by 2030. Promoting a healthier diet will be an important way to tackle the problem.

For CRI, I'm Dominic Swire.