Artificial sweeteners such as aspartame and saccharin have long been touted as healthier, lower-calorie alternatives to the added sugars found in processed foods and beverages. But now, scientists at the University of Minnesota are calling those claims into question. Their study, which was published in the International Journal of Obesity in July, found a link between long-term use of the artificial sweeteners aspartame and saccharin and an increase of fat stores in the abdomen and fat within muscle tissue.
As part of the ongoing Coronary Artery Risk Development in Young Adults (CARDIA) study, the researchers followed 3,088 men and women with a mean age of 25.2 years at the beginning of the study. Over 20 years, the research team examined their regular dietary intake, paying particular attention to non-nutritive sweeteners commonly found in artificial sweeteners.
Participants filled out validated diet history questionnaires at baseline, year 7, and year 20. After 25 years, researchers used CT scans to assess volumes of the volunteers’ visceral (VAT), intermuscular (IMAT), and subcutaneous adipose tissue (SAT). They found that long-term consumption of aspartame, saccharin, and diet beverages was linked to increased fat stores in the abdomen and fat within muscle.
Additionally, they found that total artificial sweetener, saccharin, aspartame, and diet beverage intakes were associated with greater body mass index, body weight, and waist circumference—and greater increases of these measures—over the course of the study.
“This study showed that habitual, long-term intake of total and individual artificial sweetener intakes are related to greater volumes of adipose tissue, commonly known as body fat,” said researcher Brian Steffen, PhD, MSCR, of the University of Minnesota Medical School. “This was found even after accounting for other factors, including how much a person eats or the quality of one’s diet.”
The study’s findings challenge many assumptions about the potential health benefits of artificial sweeteners, including recommendations from the American Diabetes Association and the American Heart Association that promote the replacement of added sugars with artificial sweeteners. Based on their results, the researchers recommend considering alternative approaches, as long-term artificial sweetener consumption may have potential health consequences.
“This is an especially timely study, given the World Health Organization’s recent warning of the potential health risks of aspartame,” said principal investigator Lyn Steffen, PhD, MPH, of the University of Minnesota School of Public Health. “These findings underscore the importance of finding alternatives to artificial sweeteners in foods and beverages, especially since these added sweeteners may have negative health consequences.”
Steffen’s team emphasizes the need for more studies to better understand the connection between artificial sweetener intake and increased body fat. Further research is warranted to explore the underlying mechanisms and gain clearer insights into how dietary habits affect metabolic health. That said, they write in their conclusion, “alternatives to national recommendations to replace added sugar with [artificial sweeteners] should be considered since both may have health consequences.”