Monosodium Glutamate: Review on Preclinical and Clinical Reports

Abstract

Monosodium glutamate (MSG) is a flavor enhancer derived from L-glutamic acid, a naturally occurring amino acid in various food products. Although MSG is generally considered safe by food safety regulatory agencies, it is claimed that MSG administration may lead to neurotoxicity, cardiotoxicity, hepatic and renal disorders, and metabolic disorders. This review aimed to provide a comprehensive perspective on the potential risks of MSG administration, based on results obtained from preclinical and clinical studies regarding the alleged toxic effects of MSG. A literature search was conducted in Scopus, Google Scholar, Pubmed, and ScienceDirect databases for preclinical and clinical studies that evaluated the adverse effects of MSG administration on health. Preclinical studies showed that MSG administration was associated with obesity, cardiotoxicity, hepatotoxicity, kidney toxicity, neurotoxicity, anemia, spleen toxicity, lipid and glucose metabolism alteration, negative effects of fertility, coagulant system, and microbiota. However, clinical studies have focused mostly on MSG effects on appetite and energy expenditure. Additionally, MSG administration was associated with obesity, neurotoxicity, and increasing pain symptoms whereas did not affect the microbiota. Also, MSG can be used as a therapeutic agent in dementia patients by showing a positive effect on cognitive performance.