The study data, published in Diabetologia, investigates a possible link between consumption of sweetened sodas and other drinks and type 2 diabetes in a large European population, after several US-focused studies suggested an association.
Led by Dr Dora Romaguera from Imperial College London, UK, and her colleagues in the InterAct consortium, the team analysed data on the consumption of juices and nectars, sugar-sweetened soft drinks and artificially sweetened soft drinks in more than 28,000 people from eight European populations participating in the European Prospective Investigation into Cancer and Nutrition (EPIC study).
“In European men and women, one 12 oz daily increment in sugar-sweetened soft drink consumption was associated with a 22% increase in hazard ratio [risk] for type 2 diabetes,” wrote Romaguera and her colleagues - however they noted that this was reduced to 18% after BMI and caloric intake were taken into account.
"Given the increase in sweet beverage consumption in Europe, clear messages on the unhealthy effect of these drinks should be given to the population,” she added.
Professor Nick Wareham from the University of Cambridge, UK who leads the InterAct consortium added that the finding comes from the largest study of this issue in Europeans “and adds to a growing global literature suggesting that there is a link between consumption of sugar-sweetened beverages, obesity and risk of development of type 2 diabetes.”
“Together with observations from randomised controlled trials, this observation suggests that consumption of these beverages should be limited as part of an overall healthy diet,” he said.
However, Glenys Jones, nutrition communications manager at Sugar Nutrition UK suggested to FoodNavigator that a 16 year follow-up period after a single questionnaire to identify nutritional habits was not enough to offer insight.
“Over a 16 year period people will have consumed a vast array of different foods and drinks, and products will have also been reformulated,” said Jones. “Therefore, it is impossible to isolate the effect of any one product from a single questionnaire completed at the beginning of this 16 year time-frame.”
She also noted that a population based study such as this “is unable to determine any cause and effect relationships, particularly when dietary habits are complex and so closely linked with other lifestyle choices.”
The new study included 12,403 type 2 diabetes cases and a random sub-cohort of 16,154 identified within the EPIC study.
The team found that, after adjusting for confounding factors, consumption of one 12oz (336ml) serving size of sugar-sweetened soft drink per day increased the risk of type 2 diabetes by 22%. This increased risk fell slightly to 18% when total energy intake and body-mass index (BMI) were accounted for.
The authors also observed a statistically significant increase in type 2 diabetes incidence related to artificially sweetened soft drink consumption, however this significant association disappeared after adjusting for confounders, they said.
“One 12 oz daily increment in artificially sweetened soft drinks was associated with a 52% increase in hazard ratio,” said Romaguera and her team – however they added that further adjustment for BMI and caloric intake removed the risk associated with artificially sweetened soft drinks, while the link between sugar-sweetened soft drink consumption and diabetes persisted.
They suggested that this ‘probably’ indicates that the association between artificially sweetened soda and diabetes was not causal – but driven by the weight of participants.
Pure fruit juice and nectar consumption was not significantly associated with diabetes incidence.
“The bottom line is that sugary soft drinks are not good for you – they have no nutritional value and there is evidence that drinking them every day can increase your relative risk for type 2 diabetes,” commented Professor Patrick Wolfe at University College London, UK.
“But your overall likelihood of developing type 2 diabetes will depend on your individual risk factors – primary among them your weight and level of physical fitness,” he said.
Published online ahead of print, doi: 10.1007/s00125-013-2899-8
"Consumption of sweet beverages and type 2 diabetes incidence in European adults: results from EPIC-InterAct"
Authors: InterAct Consortium