The large European study found that people who have more than two sodas a day - with or without sugar - had a higher risk of dying over about 16 years than people who sipped the fizzy beverages less than once a month.
"We found that higher soft drink intake was associated with a greater risk of death from any cause regardless of whether sugar-sweetened or artificially sweetened drinks were consumed," said study senior author Neil Murphy. He's a scientist with the International Agency for Research on Cancer in Lyon, France.
"Our results for sugar-sweetened soft drinks provide further support to limit consumption and to replace them with healthier beverages, preferably water," Murphy said.
How might sodas raise your risk of dying?
Sugar-sweetened beverages may lead to weight gain and obesity. They also may affect the way the hormone insulin is used in the body, which can lead to inflammation, Murphy noted. All of these things can lead to health conditions that may shorten life.
He said more research is needed to understand how artificially sweetened soda might increase the risk of early death.
While it found an association, the current study does not prove a cause-and-effect relationship between soda and a higher risk of early death. It's possible that soda drinkers have other habits that could add to their odds, such as smoking or a less healthy diet.
This study isn't the first to find a connection between soda and bad health outcomes. Two recent studies - one from BMJ and the other in Circulation - linked drinking soda to cancer and deaths from heart disease.
The current research included more than 451,000 people from 10 European countries. Their average age was 51. Researchers followed the participants' health for an average of 16 years.
In addition to a higher risk of dying from all causes for those who drank more than two sodas a day, more sodas were also linked to some specific causes of death.
- People who had more than one soda daily - sugar-sweetened or artificially sweetened - compared to fewer than one a month had a higher risk of dying from colon cancer and Parkinson's disease.
- People who had more than one sugar-sweetened soda a day compared to fewer than one a month had a higher risk of dying from digestive diseases.
- People who had more than artificially sweetened soda a day compared to less than one a month had a higher risk of dying from circulatory diseases like heart disease.
Murphy said researchers tried to account for factors such as body mass index (an estimate of body fat based on height and weight) and smoking, and still found an association between drinking more soda and a higher risk of dying.
Representatives of the beverage and sweetener industries urged people not to overreact to the findings.
Low-calorie and no-calorie sweeteners are "an important tool for weight management and those managing diabetes," said Robert Rankin, president of the Calorie Control Council.
The council's medical adviser, Dr. Keri Peterson, added: "The safety of low- and no-calorie sweeteners has been reaffirmed time and time again by leading regulatory and governmental agencies around the world."
William Dermody Jr., a spokesman for the American Beverage Association, offered a similar view. "Soft drinks are safe to consume as part of a balanced diet and the authors of this study acknowledge their research does not indicate otherwise."
But Dr. Maria Anton, an endocrinologist at Northwell Health's Long Island Jewish Forest Hills Hospital, said excess consumption of soft drinks and other high-sugar and artificially sweetened beverages has become the norm for many people.