Background: There is growing evidence of the involvement of the kynurenine
metabolic pathway and the enhancement of kynurenic acid production in the neuroprotective
effects of the ketogenic diet.
Objective: Here, we review evidence implicating kynurenic acid in the efficacy of ketogenic
diet in eye diseases associated with neurodegeneration.
Findings: Ketogenic diet and ketone bodies that are elevated during exposure to the ketogenic
diet each have a neuroprotective effect on retinal ganglion cells in a rat model of Nmethyl-
D-aspartate induced neuronal damage. Chronic exposure to ketogenic diet also increases
kynurenic acid concentrations in discrete rat brain structures. A non-selective glutamate
receptor agonist, glutamate, also decreases the production of kynurenic acid in bovine
retinal slices; this effect is attenuated by acetoacetate and β-hydroxybutyrate, two of
three ketone bodies overproduced during ketogenic diet.
Perspective: Whether ketogenic diet induced enhancement of kynurenic acid production
would translate into a clinically significant improvement in certain eye diseases like glaucoma
and retinal neurodegenerations awaits further experimental and clinical verification.