October 27, 2020
Sugary and artificially sweetened drinks are each associated with an increased risk of developing cardiovascular disease, according to results from a large prospective cohort study.
However, the design of that study fails to take into account other sources of dietary sugar, according to one expert.
In a research letter published online October 26 in the Journal of the American College of Cardiology, Eloi Chazelas, a PhD candidate at Sorbonne Paris Nord University in Paris, and colleagues, shared results from nearly 105,000 subjects (79% women; mean age, 43 at baseline; median follow-up, 6.6 years) enrolled in the NutriNet-Sante cohort study.
In this observational study, which began recruiting in 2009, dietary patterns are self-reported by subjects, while health outcomes are validated by investigators.
Chazelas and his colleagues identified 1379 first incident cases of stroke, transient ischemic attack, myocardial infarction, acute coronary syndrome, and angioplasty in the cohort during 2009-2019. Cases that occurred during the first 3 years' follow-up were excluded from the analysis, to avoid potential reverse causality bias.
After adjustment for a wide range of dietary, demographic and health confounders, the investigators found that high consumers of sugary drinks or artificially sweetened drinks saw 20% and 32% higher risk of such events, respectively, compared with people who reported drinking neither beverage type (hazard ratio [HR], 1.20; 95% CI, 1.04-1.40; P for trend < .0009 and HR, 1.32; 95% CI, 1.00-1.73; P for trend < .03).
Sugary drinks were defined as containing 5% or more of sugars, including natural fruit juices. The high consumers in the study had a median intake of 185 mL per day of sugary drinks, or 176 mL per day for artificially sweetened drinks. Natural noncaloric sweeteners such as Stevia were included in the artificially sweetened group.
The findings, Chazelas and colleagues wrote in their analysis, add to evidence that artificially sweetened beverages "might not be a healthy substitute for sugary drinks." While research has suggested that artificial sweeteners induce glucose intolerance by disturbing gut microbiota, they noted, more and bigger studies are needed to understand the mechanisms by which they might bear on cardiovascular disease risk.
Robert A. Vogel, MD, of the University of Colorado Denver, urged caution in interpreting the researchers' results. In an interview, Vogel, a preventive cardiologist, said that it is "notoriously difficult" to evaluate what a food or food group does to the body outside of a carefully controlled trial. What little randomized trial evidence exists comparing the health effects of artificially sweetened and sugary drinks includes a 2012 trial in children that found diet drinks associated with reductions in body fat -- if anything a positive indication for heart health.
With adults enrolled in an observational study, things are much more easily confounded, Vogel said. "So subjects self-report that they're not consuming one thing -- sugary or sweetened beverages. What else are they putting into their diet? Maybe they're eating dessert and consuming sugar that way. Try as you will to unconfound, to do a multivariate correction for all these factors is just very difficult."
In addition, Vogel noted, the investigators made no attempt to discern among the different sweeteners consumed. "Stevia, saccharine, Sucralose -- it's highly unlikely that each of these agents has the same effect on gut microbiota."
In 2019, researchers led by Chazelas looked at cancer risk in high consumers of the sugary and artificially sweetened drinks in some 107,000 patients from the cohort, and reported that sugary drinks were significantly associated with the risk of overall cancer. They saw no similar association for artificially sweetened drinks.
The NutriNet-Sante study is funded by the French government, and the investigators disclosed no financial support from commercial entities. Vogel has received research support from Sanofi and speaking fees from Regeneron.