The consumption of sugary drinks and 100% fruit juices was positively associated with the risk of overall cancer and breast cancer, found a nine-year French observational study.
For some time now, researchers have been linking sugary drinks with a wide range of health risks, reports Medical News Today. Obesity, type 2 diabetes, and cardiovascular disease are only some of the conditions that previous studies have associated with sweetened drinks. Some studies in rodents have suggested that the added sugar in soft drinks can drive the spread of cancer and fuel tumour growth.
Now, the report says, new research further explores the link between sugary drinks and cancer. The observational study finds an association between high intake of sugary drinks and cancer.
Eloi Chazelas, from the Sorbonne Paris Cité Epidemiology and Statistics Research Centre in France, is the first author of the study. Chazelas and team examined the links between the intake of sugary drinks and various forms of cancer in 101,257 French adults aged 42 years, on average. The researchers obtained the data from the NutriNet-Santé study.
The report says the drinks they examined included “sugar-sweetened beverages” such as soft drinks, syrups, fruit drinks, 100% fruit juices without any added sugar, milk-based sugary drinks, sports drinks, and energy drinks. The researchers also considered artificially-sweetened drinks, that is, “all beverages containing non-nutritive sweeteners, such as diet soft drinks, sugar-free syrups, and diet milk-based beverages.”
Using 24-hour online food questionnaires, the researchers assessed the participants’ consumption of 3,300 different kinds of foods and drinks. Furthermore, clinical observation of the participants continued for up to 9 years. During this time, the researchers looked at the risk of “overall, breast, prostate, and colorectal cancer.”
The report says Chazelas and colleagues accounted for potential confounders, including age, sex, education, hereditary risk of cancer, and lifestyle factors – such as smoking behaviour and exercise patterns.
Over the follow-up period, 2,193 people developed cancer for the first time; they were 59 years old at the time of diagnosis, on average. Among all these cases were 693 of breast cancer, 291 of prostate cancer, and 166 colorectal cancer.
The analysis revealed that for a daily increase of 100 millilitres in the intake of sugary drinks, the risk of overall cancer rose by 18%, and the risk of breast cancer increased by 22%.
The report says when the researchers analysed the risk for 100% fruit juices separately, these also elevated the risk of overall cancer and breast cancer. However, the study found no links with colorectal cancer or prostate cancer.
By contrast, diet drinks did not increase cancer risk. The scientists explain that people who consumed diet drinks did so in very small amounts, so they suggest interpreting this particular result with caution.
The report says Chazelas and colleagues also lay out the strengths and weaknesses of their research. First, the “large sample size and its detailed and up-to-date assessment” of the drinks consumed strengthen the results, write the researchers. However, the findings may not be widely generalisable, as the study cohort is not representative of the wider population, they continue.
“Since the participants of the NutriNet-Santé cohort were more often women,” they say, “with health-conscious behaviours and higher socio-professional and educational levels than the general French population, this might have resulted in a lower cancer incidence compared with national estimates.”
Other limitations include the inability to determine causality and potential measurement biases. However, the authors speculate that sugary drinks may raise cancer risk because the sugar affects visceral fat, blood sugar, and inflammatory markers – all of which previous studies have correlated with higher cancer risk.
According to the report, the researchers conclude: “These data support the relevance of existing nutritional recommendations to limit sugary drink consumption, including 100% fruit juice, as well as policy actions, such as taxation and marketing restrictions targeting sugary drinks, which might potentially contribute to the reduction of cancer incidence.”
Objective: To assess the associations between the consumption of sugary drinks (such as sugar sweetened beverages and 100% fruit juices), artificially sweetened beverages, and the risk of cancer.
Design: Population based prospective cohort study.
Setting and participants: Overall, 101 257 participants aged 18 and over (mean age 42.2, SD 14.4; median follow-up time 5.1 years) from the French NutriNet-Santé cohort (2009-2017) were included. Consumptions of sugary drinks and artificially sweetened beverages were assessed by using repeated 24 hour dietary records, which were designed to register participants’ usual consumption for 3300 different food and beverage items.
Main outcome measures: Prospective associations between beverage consumption and the risk of overall, breast, prostate, and colorectal cancer were assessed by multi-adjusted Fine and Gray hazard models, accounting for competing risks. Subdistribution hazard ratios were computed.
Results: The consumption of sugary drinks was significantly associated with the risk of overall cancer (n=2193 cases, subdistribution hazard ratio for a 100mL/d increase 1.18, 95% confidence interval 1.10 to 1.27, P<0.0001) and breast cancer (693, 1.22, 1.07 to 1.39, P=0.004). The consumption of artificially sweetened beverages was not associated with the risk of cancer. In specific subanalyses, the consumption of 100% fruit juice was significantly associated with the risk of overall cancer (2193, 1.12, 1.03 to 1.23, P=0.007).
Conclusions: In this large prospective study, the consumption of sugary drinks was positively associated with the risk of overall cancer and breast cancer. 100% fruit juices were also positively associated with the risk of overall cancer. These results need replication in other large scale prospective studies. They suggest that sugary drinks, which are widely consumed in Western countries, might represent a modifiable risk factor for cancer prevention.
Eloi Chazelas, Bernard Srour, Elisa Desmetz, Emmanuelle Kesse-Guyot, Chantal Julia, Valérie Deschamps, Nathalie Druesne-Pecollo, Pilar Galan, Serge Hercberg, Paule Latino-Martel, Mélanie Deschasaux, Mathilde Touvier