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Comment to: “Effect of monosodium L-glutamate (umami substance) on cognitive function in people with dementia”

European Journal of Clinical Nutrition volume 73, page 966 (2019)Cite this article

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Kouzuki et al. (2019) [1] examined the effect of continuous MSG ingestion on cognitive function and dietary score in patients with dementia. From their results, one of their findings suggested that continued ingestion of MSG has an effect on cognitive function. It is known that dementia of varying etiologies have different diagnosis criteria [2], which may cause variations in cognitive function [3], and may be governed by different cerebral metabolic pathways [4]. Participants in this study differed with respect to diagnosis. This variation may have induced confounding due to the fact that not all patients with dementia are the same. The authors used the TDAS, a modified version of an Alzheimer’s scale as a measure of cognitive symptoms, but it is unclear if this measure has been validated in all dementia populations. Stratification by dementia type may not have been possible due to the small number of subjects with vascular and Lewy Body dementia, but recruitment of more subjects with different types of dementia may be helpful in future studies.

Lastly, subjects ingested either MSG or NaCl through addition to foods served at breakfast, lunch, or dinner, but it is uncertain whether participants were actually taking in the prescribed amounts. Although meals were prepared by staff under the supervision of a nutritionist, previous research has shown that elderly people with mild cognitive impairment or dementia are at risk for malnutrition despite being served food with adequate nutrient content [5, 6]. Because they may not eat the full amount of food that is served, it is important to ensure the measurement of absolute intake levels. In future studies, it may be beneficial to use 24-h urinalysis recovery biomarkers as a comprehensive measure of MSG or NaCl intake to confirm that the desired amounts of MSG and NaCl are being consumed.

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References

  1. Kouzuki M, Taniguchi M, Suzuki T, Nagano M, Nakamura S, Katsumata Y, et al. Effect of monosodium L-glutamate (umami substance) on cognitive function in people with dementia. Eur J Clin Nutr. 2019;73:266–75.

    Article  CAS  Google Scholar 

  2. Yoshitake T, Kiyohara Y, Kato I, Ohmura T, Iwamoto H, Nakayama K, et al. Incidence and risk factors of vascular dementia and Alzheimer’s disease in a defined elderly Japanese population. Hisayama Study. 1995;45:1161–8.

    CAS  Google Scholar 

  3. Walker MP, Ayre GA, Cummings JL, Wesnes K, McKeith IG, O’Brien JT, et al. Quantifying fluctuation in dementia with Lewy bodies, Alzheimer’s disease, and vascular dementia. Neurology. 2000;54:1616–25.

    Article  CAS  Google Scholar 

  4. Minoshima S, Foster NL, Sima AA, Frey KA, Albin RL, Kuhl DE. et al.Alzheimer's41 disease versus dementia with Lewy bodies: cerebral metabolic distinction with autopsy confirmation. Ann Neurol. 2001;50:358–65.

    Article  CAS  Google Scholar 

  5. Orsitto G, Fulvio F, Tria D, Turi V, Venezia A, Manca C. Nutritional status in hospitalized elderly patients with mild cognitive impairment. Clin Nutr. 2009;28:100–2.

    Article  Google Scholar 

  6. Suominen M, Laine A, Routasalo P, Pitkala K, Rasanen L. Nutrient content of served food, nutrient intake and nutritional status of residents with dementia in a Finnish nursing home. J Nutr Health Ageing. 2004;8:234–9.

    Google Scholar 

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  1. Indiana University, Bloomington, IN, 47405, USA

    Kellee Harper-Hanigan

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  1. Kellee Harper-Hanigan
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Correspondence to Kellee Harper-Hanigan.

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Harper-Hanigan, K. Comment to: “Effect of monosodium L-glutamate (umami substance) on cognitive function in people with dementia”. Eur J Clin Nutr 73, 966 (2019). https://doi.org/10.1038/s41430-019-0433-x

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