In 2002, Ohguro et al. found that rats fed 10 grams of sodium glutamate (97.5% sodium glutamate and 2.5% sodium ribonucleotide) added to a 100 gram daily diet for as little as 3 months had a significant increase in amount of glutamic acid in vitreous, had damage to the retina, and had deficits in retinal function (27).
Ohguro et al. also documented the cumulative effect of damage caused by daily ingestion of the food additive called monosodium glutamate or MSG.
Other reports of toxic effects of monosodium glutamate on the retina have come from studies at the University of Pecs, Hungary, where the neuroprotective effects of PACAP in the retina have been studied (28,29).
27. Ohguro H, Katsushima H, Maruyama I, et al. A high dietary intake of sodium glutamate as flavoring (Ajinomoto) causes gross changes in retinal morphology and function. Exp Eye Res. 2002;75(3):307-15.
28. Babai N, Atlasz T, Tamas A, et al. Search for the optimal monosodium glutaamte treatement schedule to study the neuroprotective effects of PACAP in the retina. Ann N Y Acad Sci. 2006;1070(July):149-155.
29. Szabadfi K, Atlasz T, Horvath G, et al. Early postnatal enriched environment decreases retinal degeneration induced by monosodium glutamate treatment in rats. Brain Res. 2009;1259(March):107-12.
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53. Hamatsu T. Experimental studies on the effect of sodium iodate and sodium L-glutamate on ERG and histological structure of retina in adult rabbits. Acta Soc Ophthalmol Jpn. 1964;68(11):1621-1636. (Abstract)
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55. Cohen AI. An electron microscopic study of the modification by monosodium glutamate of the retinas of normal and "rodless" mice. Am J Anat. 1967;120(2):319-356.
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