Core Viewpoint - The article discusses the increasing consumption of fructose and its potential health risks, particularly its role in aggravating inflammation and its association with various diseases, including cancer and metabolic disorders [2][3][4]. Group 1: Fructose Consumption and Health Risks - Fructose is a monosaccharide that has been widely used as a sweetener in beverages and processed foods, leading to a significant increase in its consumption over the past 50 years [2]. - Excessive intake of fructose is linked to various health issues, including high blood sugar, obesity, type 2 diabetes, fatty liver, cardiovascular diseases, and an increased risk of certain cancers such as colorectal, pancreatic, ovarian, and liver cancer [2][3]. - Recent studies indicate that high fructose consumption may also be associated with anxiety disorders, particularly among adolescents [2]. Group 2: Immune System Impact - The impact of fructose on the immune system, particularly its role in regulating acquired immunity and T cell immunity, has not been sufficiently studied [3][6]. - A recent study found that high fructose intake promotes the generation of effector T cells (Th1 and Th17), exacerbating inflammation and potentially worsening inflammatory bowel disease (IBD) [4][7]. - The study suggests that the common antidiabetic drug metformin can reverse the effects of high fructose intake by inhibiting mTORC1 activation and reducing reactive oxygen species (ROS) mediated TGF-β activation, thus alleviating T cell inflammation and colitis [4][9]. Group 3: Mechanisms of Fructose-Induced Inflammation - High fructose intake enhances the differentiation of Th1 and Th17 cells through a glutamine metabolism-dependent pathway that activates mTORC1, contributing to the progression of IBD [7]. - The study highlights that fructose can directly mediate immune responses and disrupt immune homeostasis, leading to increased inflammation [9]. Group 4: Fructose and Cancer Growth - Additional research indicates that fructose may indirectly promote tumor growth by enhancing lipid transfer between organs, providing cancer cells with the necessary lipids for rapid proliferation [13]. - Another study reveals that fructose inhibits the polarization of M1-like tumor-associated macrophages, promoting the development of colorectal cancer through mechanisms that do not rely on its downstream metabolites [15].