Fructose metabolism

"Fructose metabolism," or fructolysis, refers to the biochemical pathway by which the monosaccharide fructose is processed primarily in the liver but also in kidney proximal tubule cells and small bowel enterocytes. The process begins with phosphorylation of fructose by **fructokinase** to form **fructose 1-phosphate**, which is then cleaved by **aldolase B** into dihydroxyacetone phosphate (DHAP) and glyceraldehyde. These intermediates feed into glycolysis or gluconeogenesis pathways for energy production or conversion into glycogen and triglycerides. Unlike glucose metabolism, which is tightly regulated at phosphofructokinase, fructolysis bypasses this control point—leading to rapid processing that can promote lipid synthesis when dietary intake is high. Deficiencies of key enzymes such as aldolase B result in inherited metabolic diseases like hereditary fructosuria or hereditary fructose intolerance. Chronic excessive dietary intake of fructose has been implicated in several metabolic diseases including obesity, insulin resistance, type 2 diabetes mellitus, non-alcoholic fatty liver disease (NAFLD), and metabolic syndrome due to its effects on hepatic lipid accumulation and systemic energy balance[1][2][3][4][5].

Other names

Fructolysis