The dietary administration of monosodium glutamate or glutamic acid to C-57 black mice for two years

l-Monosodium glutamate, dl-monosodium glutamate (dl-MSG) and l-glutamic acid (l-GA) were each incorporated at levels of 1.0 and 4.0% w/w in the diets of male C-57 black mice for 715 days. Mortality and disease, some of which was attributable to fighting and attendant injury, did not differ significantly from the findings in control mice, and there was no evidence of malignancy. The only tumour detected was a single benign adenoma of the lung in a mouse receiving 1% dl-MSG.