Rehovot, Israel—A recent study published in Nature suggests that artificial sweeteners may be playing a role in the obesity epidemic, but some are questioning the findings.The Weizmann Institute’s Eran Elinav, Ph.D, who headed the research revolving around this study, believes that the mechanism behind this may be changes in the composition of gut microbiota brought on by artificial sweeteners. Even though artificial sweeteners do not contain sugar, the belief from the authors of this study is that they still affect the body’s ability to utilize glucose, leading to glucose intolerance, which in turn leads to adult-onset diabetes and metabolic syndrome.

The study itself involved giving mice water laced with three common artificial sweeteners in equivalent amounts to those permitted by the FDA, then repeating the process with different types of mice and amounts of sweeteners. In all cases, the mice developed glucose intolerance. The conclusion that gut microbiota played a role in this intolerance was based off of a previous hypothesis. In order to test this, the glucose intolerant mice were given antibiotics to wipe their microbiota, which resulted in a full reversal of the previous effects. The microbiotas were then transferred to a new group of mice, which resulted in them also generating glucose intolerance. Elinav and co-leader Professor Eran Segal also noted that data from their previous Personalized Nutrition Project also suggested a significant association between self-reported consumption of artificial sweeteners, personal configurations of gut bacteria and the propensity for glucose intolerance, which was supported by a smaller human trial administered afterwards

However, some have been quick to question these findings, finding issue with the nature of the study itself. Haley Curtis Stevens, Ph.D, president of the Calorie Control Council, said that “The study suffers from small sample sizes, unrealistic sweetener applications and doses, and a dependence largely on rodent research. Findings should be interpreted with caution.” Aspartame supplier Ajinomoto also noted that the findings published in the study “ignore the large body of science which demonstrates that low calorie alternatives help people to control their weight.” There were also several objections over the human trials, which had no control group, a small sample size, and a very short study period.

Published in WholeFoods Magazine, December 2014 (online 10/13/14)