Furthermore, the risk rises with each drink; every extra can increases the danger by more than a fifth. Experts have called for greater warnings of the “unhealthy effects” of soft drinks enjoyed by millions of Britons every day.
Lead researcher Dr Dora Romaguera, from Imperial College London, warned that one problem with fizzy drinks was that they did not fill you up, so people were tempted to consume more of them.
“They should be seen as a treat you have once every couple of weeks, not as a substitute for water every time you feel thirsty,” she said.
Previous research has shown how sugary drinks can dramatically increase the risk of stroke, heart attacks and long-term liver damage similar to chronic alcohol abuse.
A typical can of fizzy drink has 150 sugar-based calories which are far more dangerous to the body than those from other sources, it was discovered.
A team from Imperial College looked at the link between sweet beverages and Type 2 diabetes in Europe, as much previous research had been carried out in North America. They tracked their consumption by 350,000 people across eight European countries, including Britain.
The researchers found that one 12oz (336ml) serving increased the risk of Type 2 diabetes, with every additional drink raising it by 22% compared with having one can a month or less.
This risk fell to 18% when body-mass index was accounted for, suggesting that those who were heavier tended to drink more soft drinks and were more at risk of developing diabetes anyway.
The team also found a significant increase related to drinking artificially sweetened soft drinks.
Romaguera added, “Given the increase in sweet beverage consumption in Europe, clear messages on the unhealthy effect of these drinks should be given to the population.”
Dr Matthew Hobbs, head of research at Diabetes UK, said, “The finding that people who drank more sugar-sweetened soft drinks were at higher risk of developing Type 2 diabetes, even when body mass index was taken into account, suggests the increased risk was not solely due to the extra calories in those drinks. The large number of people involved in this study means this finding is extremely unlikely to have happened by chance.
“It is not definitive evidence that sugar-sweetened soft drinks increase the risk of Type 2 diabetes, other than through their effect on body weight.
“We do though already recommend limiting consumption of sugary foods and drinks as these are usually high in calories and so can lead to weight gain if you have too many of them.
“This is important for Type 2 diabetes because we know that maintaining a healthy weight is the single most important thing you can do to prevent it.”
Gavin Partington, of the British Soft Drinks Association, said, “It is well-known that diabetes is the result of many different factors, including obesity and family history.
“This study does not look at causation and cannot tell us if consuming soft drinks, or any other food or drink, is a further cause of diabetes.
“The survey is based on information about people’s food choices up to 16 years old, which is not a very good guide to what people are eating and drinking today.
“Soft drinks are safe to consume but, like all other food and drink, should be consumed in moderation as part of a balanced diet.”