While the traditional goal of sugar substitutes has been to assist dieters and diabetics, new evidence from a research study led by investigators at Cornell University, Braunschweig University of Technology, Germany, and the University of Luxembourg has provided data that contradicts long-standing assumptions that the sugar alcohol erythritol is not metabolized by the body.
The findings from this new study—published recently in Proceedings of the National Academy of Sciences in an article entitled “Erythritol Is a Pentose-Phosphate Pathway Metabolite and Associated with Adiposity Gain in Young Adults”—identify the alternative sweetener as a biomarker for increasing fat mass and show that it is even produced in humans.
Erythritol is 60% to 70% as sweet as sucrose, yet it is generally considered noncaloric and does not affect blood sugar. Prior studies claimed no endogenous synthesis. We report a previously unrecognized metabolism of glucose to erythritol, and given the association between erythritol and weight gain, research is needed to understand whether and how this pathway contributes to weight gain risk.
The prevention of weight gain in adulthood is a public health challenge, particularly given the difficulty of losing weight. Data on freshmen were collected at the beginning and end of the academic year, and baseline blood samples were studied to find markers of incident weight gain. A metabolite, erythritol, was elevated at the beginning of the year in freshmen who went on to gain weight, fat, and abdominal fat compared with freshmen with stable weight.
In the current study, the investigators conducted a discovery-based analysis to identify metabolomic markers associated with weight gain and increase in fat mass in young adults during the transition to college life. Researchers found that students who gained weight and abdominal fat over the course of the year had 15-fold higher blood erythritol at the start of the year compared with their counterparts who were stable or lost weight and fat mass over the academic year.
“Blood samples and anthropometry measurements were collected in the first 3 d[ays] on campus and at the end of the year,” the authors wrote. “Plasma from individuals was pooled by phenotype [incident central adiposity, stable adiposity, baseline hemoglobin A1c (HbA1c) >5.05%, HbA1c <4.92%] and assayed using GC-MS [gas chromatography–mass spectrometry], chromatograms were analyzed using MetaboliteDetector software, and normalized metabolite levels were compared using Welch’s t test. Assays were repeated using freshly prepared pools, and statistically significant metabolites were quantified in a targeted GC-MS approach.”
The study took place as part of Cornell's EnHANCE project—an initiative of the Division of Nutritional Sciences that seeks to understand how the transition to college affects changes in diet, weight, and metabolism. The findings from this ongoing endeavor are used to advance knowledge on the impacts to student health through the undergraduate years and beyond.
“About 75% of this population experiences weight gain during the transition,” explained senior study investigator Patricia Cassano, Ph.D., professor in the Division of Nutritional Sciences at Cornell. “With this in mind, it is important to identify biomarkers of risk that could guide its understanding and prevention.”
Each fall, more than 3 million high school graduates enroll in postsecondary education as first-time college freshmen, and this transition to a residential college environment is associated with weight gain.
“With the finding of a previously unrecognized metabolism of glucose to erythritol and given the erythritol-weight gain association, further research is needed to understand whether and how this pathway contributes to weight-gain risk,” Dr. Cassano concluded.