A new study conducted in France has recently discovered that even a small consumption — 100 ml or approximately a third of a can of soda — of sugary drinks like juices or sodas per day are linked to a higher risk of cancer, specifically an 18% increase for an overall cancer risk and a 22% increase in risk for breast cancer.
The research, which was published in medical journal BMJ on Wednesday, looked into the association between the consumption of sugary beverages and an increased risk in cancer by collecting data on more than 100,000 French adults with an average age of 42.
Mathilde Touvier, lead author of the study, and her team observed that the main driver for the link between these drinks and an increased cancer risk was the sugar.
“High sugary drinks consumption is a risk factor for obesity and weight gain,” Touvier, who is the research director of the Nutritional Epidemiology Research Team of the National Health and Medical Research Institute at the Paris 13 University, told CNN. “Obesity is in itself a risk factor for cancer.”
The research team looked at 101,257 healthy French adults — 79% were women and 21% men — in the ongoing French NutriNet-Santé study.
The subjects were asked to fill out at least two questionnaires and were followed over a nine-year period. Participants submitted at least two 24-hour diet recall questionnaires to fill out their typical intake of 3,300 different food and drink items, in which the research team then utilized to deduce their respective sugary drink consumption.
The daily consumption of sugar drinks (i.e. sugar-sweetened beverages and 100% fruit juices) and artificially sweetened or diet beverages were assessed and first reports of cancers by participants were affirmed by medical records and linked with health insurance national databases.
The researcher found on average, men drank more sugary drinks than women — 90.3 ml daily compared to 74.6 ml. Other risk factors for cancer, such as sex, age, family history of cancer, educational level, smoking status and amount of physical activity were also taken into account.
A total of 2,193 first cases of cancer were diagnosed during the study’s followup term, with an average age of 59 years. Among those diagnosed, 693 were breast cancers, 291 were prostate cancer cases and 166 were colon cancers.
“The results indicate statistically significant correlations between the consumption of sugar-sweetened drinks and risk of all cancers combined, and of breast cancer,” Ian Johnson, nutrition researcher and emeritus fellow at Quadram Institute Bioscience who wasn’t involved in the research, told the Science Media Centre in the U.K. “Surprisingly perhaps, the increased risk of cancer in heavier consumers of sugary drinks was observed even among consumers of pure fruit juice — this warrants more research.”
Another possible pathway sugary drinks might play a role in carcinogenesis is the additives, such as 4-methylimidazole (found in drinks that contain caramel coloring).
However, like most studies, this one is observational and cannot necessarily illustrate a cause-and-effect relationship.
According to researchers, the major limitation in the study is that it may be impossible to determine whether the link is due to a type of beverage or another hidden health issue.
“While this study doesn’t offer a definitive causative answer about sugar and cancer, it does add to the overall picture of the importance of the current drive to reduce our sugar intake,” Amelia Lake, reader in public health nutrition at Teesside University who also did not take part in the study, told the Science Media Centre. “Clearly there is more work to be done and measuring dietary intake is challenging, however, the message from the totality of evidence on excess sugar consumption and various health outcomes is clear — reducing the amount of sugar in our diet is extremely important.”
For now, Touvier suggested people should follow public health guidelines that recommend limiting sugary drinks to one glass a day, maximum.
However, in response to the study results, the American Beverage Association highlighted the safety of sugary drinks.