Pilot intervention study of a low-salt diet with monomagnesium di-L-glutamate as an umami seasoning in psychiatric inpatients.

Background: Schizophrenia patients have an elevated prevalence of stroke and cardiovascular risk factors, such as elevated body mass index, hypertension, and hyperlipidaemia. This pilot study investigated the influence of a low-sodium diet using umami seasoning on food intake and clinical parameters in schizophrenia patients.

Methods: A single-blind crossover intervention study was conducted in 15 clinical schizophrenia patients given a low-sodium diet with or without umami seasoning, monomagnesium di-L-glutamate, for 2 weeks. After the initial 2-week intervention, there was a 2-week washout period, and then the interventions were switched. Daily body weight, body mass index, abdominal circumference, blood pressure, and nutrient intake for each subject were determined.

Results: The results showed that subjects given monomagnesium di-L-glutamate had an approximately 25.9% reduction in dietary sodium. Furthermore, daily energy intake did not decrease, and no significant changes in body weight, body mass index, abdominal circumference, blood pressure, and nutrient intake were observed.

Conclusions: The use of umami seasonings, such as monomagnesium di-L-glutamate, might be an effective long-term strategy for psychiatric patients requiring restricted sodium intake.