Modelling of salt intake reduction by incorporation of umami substances into Japanese foods: a cross-sectional study.

BACKGROUND: Evidence has demonstrated that excess sodium intake is associated with development of several non-communicable diseases. The main source of sodium is salt. Therefore, reducing salt intake in foods is an important global public health effort to achieve sodium reduction and improve health. This study aimed to model salt intake reduction with 'umami' substances among Japanese adults. The umami substances considered in this study include glutamate or monosodium glutamates (MSG), calcium diglutamate (CDG), inosinate, and guanylate. METHODS: A total of 21,805 participants aged 57.8 years on average from the National Health and Nutrition Survey was used in the analysis. First, we employed a multivariable linear regression approach with overall salt intake (g/day) as a dependent variable, adjusting for food items and other covariates to estimate the contribution of salt intake from each food item that was selected through an extensive literature review. Assuming the participants already consume low-sodium products, we considered three scenarios in which salt intake could be reduced with the additional umami substances up to 30%, 60% and 100%. We estimated the total amount of population-level salt reduction for each scenario by age and gender. Under the 100% scenario, the Japan's achievement rates against the national and global salt intake reduction goals were also calculated. RESULTS: Without compromising the taste, the 100% or universal incorporation of umami substances into food items reduced the salt intake of Japanese adults by 12.8-22.3% at the population-level average, which is equivalent to 1.27-2.22 g of salt reduction. The universal incorporation of umami substances into food items changed daily mean salt intake of the total population from 9.95 g to 7.73 g: 10.83 g to 8.40 g for men and 9.21 g to 7.17 g for women, respectively. This study suggested that approximately 60% of Japanese adults could achieve the national dietary goal of 8 g/day, while only 7.6% would meet the global recommendation of 5.0 g/day. CONCLUSIONS: Our study provides essential information on the potential salt reduction with umami substances. The universal incorporation of umami substances into food items would enable the Japanese to achieve the national dietary goal. However, the reduced salt intake level still falls short of the global dietary recommendation.

The impact of social isolation from COVID-19-related public health measures on cognitive function and mental health among older adults: A systematic review and meta-analysis.

We aimed to estimate the impact of social isolation on cognitive function and mental health among older adults during the two-year-and-a-half COVID-19 period. Pubmed Central, Medline, CINAHL Plus and PsychINFO were searched between March 1, 2020, and September 30, 2022. We included all studies that assessed proportions of older adults with the mean or the median with a minimum age above 60 reporting worsening cognitive function and mental health. Thirty-two studies from 18 countries met the eligibility criteria for meta-analyses. We found that the proportions of older adults with dementia who experienced worsening cognitive impairment and exacerbation or new onset of behavioral and psychological symptoms of dementia (BPSD) were approximately twice larger than that of older adults with HC experiencing SCD and worsening mental health. Stage of dementia, care options, and severity of mobility restriction measures did not yield significant differences in the number of older adults with dementia reporting worsening cognitive impairment and BPSD, while the length of isolation did for BPSD but not cognitive impairment. Our study highlights the impact of social isolation on cognitive function and mental health among older adults. Public health strategies should prioritize efforts to promote healthy lifestyles and proactive assessments.