Even sugar-free soda linked to early death risk, French research finds

04 Sep 2019 --- Soft drink consumption, including both sugar- and artificially-sweetened drinks, has been associated with an increased risk of overall death. This is according to a new, population-based study from the International Agency for Research on Cancer based in Lyon, France. The study followed the soda-drinking habits of nearly half a million Europeans and found that consuming two or more glasses of soda daily increased the risk of early death from all causes. Although the observational design of the study warrants further research, the authors note that the findings may urge policy initiatives to limit soft drink consumption – even when it’s sugar-free.

“Our results provide additional support for the possible adverse health effects of sugar-sweetened soft drinks and suggest to replace them with other healthier beverages, preferably water. For artificially-sweetened soft drinks, we now need a better understanding of the mechanisms that may underlie this association and research such as ours will hopefully stimulate these efforts.” Dr. Neil Murphy of the International Agency for Research on Cancer, tells NutritionInsight.

“Relatively few studies have investigated the soft drinks and mortality relationship. Two large studies in the US were published earlier this year, but this is the first large-scale European study to examine these relationships,” Dr. Murphy adds.

Soft drink drinks consumption has been linked to an array of adverse health outcomes. In July, a British Medical Journal (BMJ) study noted that soft drinks may increase overall cancer risk. The study, significantly, did not look at sugar-free options. In addition, a mouse study from Cornell University found that consumption of high-fructose corn syrup – widely used in soda drinks – promotes the growth of intestinal tumors.

Soft drink drinks consumption has been linked to an array of adverse health outcomes.However, Dr. Keri Peterson, Medical Advisor to the Calorie Control Council – an international association representing the low- and reduced-calorie food and beverage industry – notes that “numerous studies have proven that low- and no-calorie sweeteners used in diet sodas are some of the safest and most thoroughly studied ingredients in the food supply. The safety of low- and no-calorie sweeteners has been reaffirmed time and time again by leading regulatory and governmental agencies around the world.”

Study specifics and limitations
Published in the journal Jama Internal Medicine, the new study monitored nearly 452,000 men and women from ten European countries, including Denmark. France, Germany, Greece, Italy, the Netherlands, Norway, Spain, Sweden and the UK. During a 16-year follow-up, 41,693 deaths occurred and the researchers found a higher all-cause mortality rate among the people who consumed two or more soda drinks a day, as opposed to those who consume less than one per month. 

Soft drink consumption was collected via food questionnaires or interviews at baseline from 1992 to 2000. A higher risk of death from circulatory diseases was also associated with consuming two or more glasses per day of total and artificially sweetened soft drinks. Moreover, a higher risk of death from digestive diseases was associated with drinking one or more glass per day of total and sugar-sweetened soft drinks. No association was observed between soft drink consumption and overall cancer death, the researchers note. 

The study has its limitations however, due to its observational design, which makes causal inferences impossible, and there was only a single assessment of soft drink consumption. 

Furthermore, in response to the new study, Robert Rankin, President of the Calorie Control Council, cautions against drawing conclusions from observational studies such as this, which attempt to associate behaviors with outcomes but cannot prove cause and effect and have significant limitations. 

Low- and no-calorie sweeteners have a long safety record and are an important tool for weight management and those managing diabetes.“In addition to not being able to prove a causal relationship between low- and no-calorie sweeteners and circulatory diseases, the researchers conducted follow up with patients 13-17 years after their original data collection. This assumes there were no changes in diet or lifestyle during this time that could impact mortality, which is unrealistic. Low- and no-calorie sweeteners have a long safety record and are an important tool for weight management and those managing diabetes. This study paints an inaccurate picture of the important role of these products for consumers.”

The International Sweeteners Association (ISA) has also issued a response to the study and has flagged its limitations. "The ISA would like to point to the observational design of this study, which, by its nature and as also acknowledged by the authors, cannot prove any cause and effect relationship. Extreme caution must therefore be applied when considering results of this type of studies, as selection bias, residual confounding and reverse causation may affect the observed associations. Furthermore, in line with the overwhelming body of scientific evidence available, the safety of all approved low calorie sweeteners has been repeatedly and consistently confirmed by regulatory authorities around the world," the statement reads.

Policing soda consumption
Governments around the world have made moves to curb soda consumption in a bid to prevent its negative health outcomes. For example, the US city of Berkley saw a 52 percent drop in the consumption of sugary drinks after it levied the nation’s first soda tax on sugar-sweetened beverages, effective since November 2014. 

Meanwhile, if the US were to implement a nation-wide soda tax, it would yield US$7 billion per year, according to an economic assessment based on an analysis of health benefits and consumer behavior. The work highlighted that a tax would bring advantages similar to those of long-standing cigarette taxes.

By Kristiana Lalou