Ketogenesis is the branch of mammalian metabolism concerned with the synthesis of
ketone bodies. In this process, the small, water-soluble compounds
acetoacetate, D-3-β-hydroxybutyrate and propanone are produced by the liver in response to reduced
glucose availability. Although
ketone bodies are always present at a low level in healthy individuals, dietary manipulation and certain pathological conditions can increase the levels of these compounds in vivo. In some instances, such as in
refractory epilepsy, high levels of
ketone bodies can be beneficial-in this instance, by exerting an
anticonvulsant effect. Conversely, if the levels of
ketones rise to supraphysiological levels, as can occur in
diabetes mellitus, a state of
ketoacidosis can occur, which has serious consequences for cellular function. More recently, research has identified a possible link between ketogenesis and
free radical-mediated pathologies, highlighting the potential application of
ketogenic diets to the treatment of conditions such as
Alzheimer's disease. Overall, an understanding of
ketone body metabolism and its links to human disease may prove to be vital in developing new regimens for the treatment of human disease.