Modelling Salt Intake Reduction with Umami Substance’s Incorporation Into Japanese Foods: A Cross-Sectional Study

Abstract

\n BackgroundEvidence has demonstrated that excess salt intake is associated with the development of several non-communicable diseases. Therefore, reformulating the sodium content of foods is an important global public health effort to achieve salt reduction and improve health. This study aimed to model sodium replacement with umami substances and estimate the possible reduction effects of the umami substances on the daily salt intake among Japanese adults. The umami substances considered in this study include glutamate or monosodium glutamates (MSG), calcium diglutamate (CDG), inosinate, and guanilate.MethodsA sample of 21,805 participants aged 57.8 years on average from the National Health and Nutrition Survey (NHNS) were used in the analysis. First, we employed a multivariable linear regression approach, with overall salt intake (g/day) as a dependent variable, adjusting for intake (g/day) from food items and other covariates, to estimate the contributions of each food item to daily salt intake. We then considered three hypothetical scenarios with varying market share percentages of umami substitute foods (30%, 60%, and 100%). We estimated the population-level salt reduction for each scenario, by age and gender, based on the contribution of each food to salt intake estimated by the regression model and the estimated salt reduction rates by food item based on an extensive literature review. Under the 100% scenario, the achievement rates for national and global dietary goals of salt intake in the Japanese population were also calculated.ResultsWithout compromising the taste, the universal incorporation of umami substances can reduce the salt intake of adult Japanese persons by 12.0-21.1% in the population level, which is equivalent to 1.27-2.22g of salt reduction. A mean daily salt intake before and after scenario in universal umami substance’s incorporation changes from 9.95g to 7.73g for the total population, from 10.83g to 8.40g for men and from 9.21g to 7.17g for women, respectively. Approximately 60% of Japanese adults could achieve the national dietary goal of 8g/day, while only 7.6% could meet the global target of 5.0g/day. ConclusionsOur study provides essential information on the potential salt reduction from sodium replacement with alternatives. The universal incorporation of umami substances into some foods could achieve the national dietary goals for the Japanese. However, the reduced salt intake level still falls short of the global dietary recommendation of 5g of salt daily.