Most people know that sugary drinks can raise blood sugar. But new research suggests they might also trigger your immune system to overreact, even after just a few days.
In a study published in Redox Biology, researchers from the University of Vienna found that drinking fructose-sweetened beverages made immune cells more sensitive to certain bacterial toxins. That reaction led to higher levels of inflammation, even in otherwise healthy people.
“The concentration of receptors for such toxins in the body increased, which means that the inflammatory response increased,” said study leader Dr. Ina Bergheim.
The researchers compared fructose (the type of sugar found in soda and many sweets) to glucose. In both human studies and lab experiments, fructose caused immune cells to produce more of a receptor called Toll-like receptor 2, which acts like an antenna for detecting threats. When that receptor picks up signals from bacterial toxins, the immune system ramps up — sometimes too much.
As a result, the body released more inflammatory chemicals, including interleukin‑6 and tumor necrosis factor, which are linked to long-term conditions like heart disease and metabolic disorders.
“These findings ... indicate that even short-term, high fructose consumption in healthy people can influence the immune system and increase inflammation,” Bergheim said.
While the study focused on short-term effects, the researchers believe that people with type 2 diabetes or fatty liver disease may be even more vulnerable to this kind of immune response.
“Sugar, especially the fructose in sugary drinks and sweets, has long been suspected of increasing the risk of developing metabolic diseases,” Bergheim said. “This needs to be investigated.”
This research was funded by institutional grants through the University of Vienna's Department of Nutritional Sciences.