Adults who drank one fizzy drink a day had a 46 per cent increased chance of developing pre-diabetes, which can lead to type 2, scientists found. Photo / Getty Images.
Drinking just one can of fizzy drink every day could have deadly consequences, scientists warn.
Adults who drank one a day had a 46 per cent increased chance of developing pre-diabetes - when the blood glucose level is higher than normal.
If diagnosed early, it can be beaten through lifestyle changes such as a healthy diet and exercise.
However, if left untreated it can lead to type 2, which, if not managed properly, can lead to devastating and fatal complications, including heart attacks.
Sugary drinks were also linked to a rise in insulin resistance, which is known to be a risk factor of type 2 diabetes.
However, diet versions of fizzy drinks did not increase the risk of developing the condition, experts found.
While the highest consumers of sugar-sweetened beverages had roughly eight per cent higher insulin resistance scores.
Even after accounting for change in weight and other aspects of diet, the relationships between sugar-sweetened beverages and these metabolic risk factors for diabetes persisted.
Lead researcher Dr Nicola McKeown said "Although our study cannot establish causality, our results suggest that high sugar-sweetened beverage intake increases the chances of developing early warning signs for type 2 diabetes.
"If lifestyle changes are not made, individuals with pre-diabetes are on the trajectory to developing diabetes.
"Our findings support recommendations to limit sugar-sweetened beverage intake, which can be achieved by replacing sugary beverages with healthier alternatives such as water or unsweetened coffee or tea.
"This is a simple dietary modification that could be of substantial health benefit to people who consume sugary drinks daily and who are at increased risk of diabetes."
Dr McKeown said more research was needed on the long-term effects of diet drinks as previous studies showed mixed results.
But she noted a huge body of research which has linked regular consumption of fizzy drinks to an increased risk of type 2 diabetes.
Study co-author Dr Jiantao Ma added "Based on our observational study alone, we cannot be certain why we saw the relationships we did.
"Additional studies are needed to fully understand the health impact of sugar-sweetened beverages and diet sodas.
"Nevertheless, our data is consistent with many other studies and clinical trials that support the health benefits of reducing sugar intake, and we encourage the public to look for healthier options."
The study was published in the Journal of Nutrition.
Professor Melanie Davies CBE, of the Leicester Diabetes Centre, who wasn't involved in the study, said "Fizzy drinks may appear to be harmless but they actually contain very high levels of sugar and, if consumed regularly, can pose a significant health risk, including increasing the risk of type 2 diabetes.
"Excessive sugar consumption is one of the major factors contributing to rising obesity levels particularly in youngsters.
"More and more people are developing type 2 diabetes at a much younger age with cases even seen in children and young people."