Observational data suggest that routine intake of non-nutritive, artificial sweeteners may be associated with increased body mass index (BMI) and cardiometabolic risk, according to research published in the Canadian Medical Association Journal (CMAJ).

Non-nutritive sweeteners, such as aspartame, sucralose and stevioside, are widely consumed, yet their long-term health impact is uncertain. Researchers synthesized evidence from prospective studies to determine whether routine consumption of non-nutritive sweeteners was associated with long-term adverse cardiometabolic effects.

Researchers searched MEDLINE, Embase and Cochrane Library (inception to January 2016) for randomized controlled trials (RCTs) that evaluated interventions for non-nutritive sweeteners and prospective cohort studies that reported on consumption of non-nutritive sweeteners among adults and adolescents. The primary outcome was BMI. Secondary outcomes included weight, obesity and other cardiometabolic end points.

From 11,774 citations, researchers included seven trials (1,003 participants; median follow-up 6 months) and 30 cohort studies (405,907 participants; median follow-up 10 years). In the included RCTs, non-nutritive sweeteners had no significant effect on BMI (mean difference −0.37 kg/m2; 95% confidence interval [CI] −1.10 to 0.36; I29%; 242 participants). In the included cohort studies, consumption of non-nutritive sweeteners was associated with a modest increase in BMI (mean correlation 0.05, 95% CI 0.03 to 0.06; I2 0%; 21 256 participants). Data from RCTs showed no consistent effects of non-nutritive sweeteners on other measures of body composition and reported no further secondary outcomes. In the cohort studies, consumption of non-nutritive sweeteners was associated with increases in weight and waist circumference, and higher incidence of obesity, hypertension, metabolic syndrome, type 2 diabetes and cardiovascular events. Publication bias was indicated for studies with diabetes as an outcome.

Researchers concluded that evidence from RCTs does not clearly support the intended benefits of non-nutritive sweeteners for weight management, and observational data suggest that routine intake of non-nutritive sweeteners may be associated with cardiometabolic risk, researchers said. Further research is needed to fully characterize the long-term risks and benefits of nonnutritive sweeteners, they added.