Aspartame may increase diabetes risk in people with obesity

Aspartame is associated with increased glucose intolerance and decreased fasting glucose in people with obesity, which can raise their risk for diabetes, according to a study published online May 24, 2016 in the journal Applied Physiology, Nutrition and Metabolism.

People with normal weight who consumed aspartame did not have these effects, researchers noted.

“Our study shows that individuals with obesity who consume artificial sweeteners, particularly aspartame, may have worse glucose management than those who don’t take sugar substitutes,” said co-author and obesity researcher Jennifer Kuk, PhD, Professor in the School of Kinesiology and Health Science at York University, in Toronto, Ontario, Canada.

Because artificial sweeteners are associated with lower caloric intake, modest reductions in body weight, and potentially lower blood glucose response, they’re commonly consumed by people with obesity and type 2 diabetes, the researchers noted. Despite the widespread use of these sweeteners, surprisingly little research has investigated their long-term health benefits, particularly when changes in body weight are considered, they added.

However, studies in animals indicated that artificial sweeteners may increase weight gain over time and may promote glucose intolerance by altering the function and composition of intestinal microbiota.

For this study, Dr. Kuk and co-author Ruth E. Brown, PhD, also of York University, analyzed data from 2,856 American adults who participated in the Third National Health and Nutrition Survey (NHANES III). Individuals reported their diet over 24 hours and identified whether they were consumers of artificial sweeteners (aspartame or saccharin), or high or low consumers of natural sugars (sugar or fructose). NHANES researchers used an oral glucose tolerance test to measure diabetes risk.

Results showed a significant association between body mass index and lower glucose tolerance in people who reported consuming aspartame. “We didn’t find this adverse effect in those consuming saccharin or natural sugars,” Dr. Kuk said.

“We will need to do future studies to determine whether any potentially negative health effects of artificial sweeteners outweigh the benefits for obesity reduction,” she added.