Kynurenic Acid and Neuroprotective Activity of the Ketogenic Diet in the Eye

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.

Here, we review evidence implicating kynurenic acid in the efficacy of ketogenic diet in eye diseases associated with neurodegeneration.

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.

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.