Even with modern medicine, infections caused by bacteria and viruses remain a leading cause of death worldwide.
Scientists are now exploring whether diet may play a role in shaping the body’s response to these threats. A research team has shown for the first time that consuming fructose causes monocytes, key immune cells in the blood, to respond more strongly to bacterial toxins in a harmful way. The study found that fructose increases the number of receptors that detect these toxins, which can intensify inflammation. The findings were published in the journal Redox Biology.
How Fructose and Glucose Affect Immune Responses
To examine how different sugars influence the immune system, researchers carried out two randomized studies involving healthy adults. Participants consumed beverages sweetened with fructose or glucose, allowing the scientists to compare how each sugar affected immune activity. Alongside these human studies, the team also performed experiments using isolated monocytes and cell culture models to better understand the biological processes involved.
Fructose Raises Receptors That Detect Bacterial Toxins
The researchers found that fructose intake, unlike glucose, increased the levels of Toll-like receptor 2 in monocytes. Toll-like receptor 2 plays an important role in regulating immune responses. As the concentration of this receptor rose, monocytes became more sensitive to lipoteichoic acid, a toxin produced by certain bacteria.
“The concentration of receptors for such toxins in the body increased, which means that the inflammatory response increased,” explains study leader Ina Bergheim from the University of Vienna. The heightened sensitivity also led to greater release of pro-inflammatory messengers, including interleukin-6, interleukin-1β, and tumour necrosis factor-alpha.
