Dietary supplementation with monosodium glutamate with dietary balance such as protein, salt and sugar intake with increasing T1R3 taste receptor gene expression in healthy females

We previously showed that chemotherapy-induced dysgeusia was associated with lingual taste receptor gene expression, and monosodium glutamate (MSG) improved dysgeusia by upregulating taste 1 receptor 3 (T1R3) gene expression. In recent years, decreased taste sensitivity has also been reported in some young people, and these are partly due to their disordered eating habits. From these background, we investigated the effects of MSG supplementation on taste receptor expression and dietary intake in healthy females. Fifteen young healthy volunteers were enrolled for the present crossover study and divided in two groups (dietary supplementation with MSG at 2.7 g/day or 0.27 g/day). The relative expression of T1R3, a subunit of both umami and sweet taste receptors, in the tongue was assessed by quantitative PCR analysis. Food intake was assessed by food frequency questionnaire (FFQg), and body composition was measured using Omron HBF-701. T1R3 expression levels in the tongue and taste sensitivity increased significantly in participants who consumed <10 g of MSG daily, whereas no alteration was observed in participants who consumed >10 g of MSG daily. Furthermore, protein, fat, and carbohydrate (PFC) balance and salt and sugar intake improved by MSG supplementation. In conclusion, MSG supplementation increased T1R3 expression in the tongue and improved dietary balance.