April 23 (UPI) -- Artificial sweeteners could be linked to diabetes and obesity, according to a study of rats and cell cultures.
Researchers at the Medical College of Wisconsin and Marquette University conducted what they believe is the largest study to assess biochemical changes caused by artificial sweeteners and sugars.
Lead researcher Brian Hoffmann, an assistant professor in the department of biomedical engineering at the Medical College of Wisconsin and Marquette University, presented the findings Sunday at the American Physiological Society annual meeting.
Artificial sweeteners are one of the most common food additives, including in diet and zero-calorie sodas.
"Despite the addition of these non-caloric artificial sweeteners to our everyday diets, there has still been a drastic rise in obesity and diabetes," Hoffman said in a press release. "In our studies, both sugar and artificial sweeteners seem to exhibit negative effects linked to obesity and diabetes, albeit through very different mechanisms from each other."
Earlier research on the negative health aspects of artificial sweeteners, including an increased risk for diabetes and for obesity, has revealed links similar to the new study, but no conclusive evidence of a cause-and-effect factor has been found.
In the latest study, researchers examined the consumption of sugar or sugar substitutes in rats and their effects on cultured cells. They also examined the impact of both on vascular health and how the substances affect the lining of blood vessels.
Rats were fed diets high in glucose or fructose, which are forms of sugar, or aspartame or acesulfame potassium, which are common zero-calorie artificial sweeteners.
Three weeks later, researchers found significant differences in the concentration of biochemicals, fats and amino acids in blood samples compared with sugar.
The body changes how it processes fat and receives energy from artificial sweeteners, the researchers report. Acesulfame potassium also accumulated in the blood, including a harmful effect on the cells that line blood vessels.
"We observed that in moderation, your body has the machinery to handle sugar; it is when the system is overloaded over a long period of time that this machinery breaks down," Hoffmann said. "We also observed that replacing these sugars with non-caloric artificial sweeteners leads to negative changes in fat and energy metabolism."
Researchers said additional studies are needed to further explain the link between artificial sweeteners and obesity and diabetes, and whether they should be avoided.
"It is not as simple as 'stop using artificial sweeteners' being the key to solving overall health outcomes related to diabetes and obesity," Hoffmann added. "If you chronically consume these foreign substances [as with sugar] the risk of negative health outcomes increases. As with other dietary components, I like to tell people moderation is the key if one finds it hard to completely cut something out of their diet."
Aisling Pigott, a dietitian and spokesperson for the British Dietetic Association, told Newsweek he would be cautious when considering the new study because a lot of the research suggesting the negative impacts of artificial sweeteners have been conducted with animals -- which have different metabolic pathways than humans. He added, however, that moderate use of any kind of sweetener is a good idea.
"We do need to be aware that overuse or excessive use of any products-including sugar or sweeteners-is not beneficial to health," Pigott said. "In addition, high levels of sweetener intake will still mean we are craving and desiring sugary foods without any 'energy intake' and there are question marks about the impact of this on satiety."