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ORIGINAL RESEARCH article

Front. Nutr.
Sec. Clinical Nutrition
Volume 11 - 2024 | doi: 10.3389/fnut.2024.1465324
This article is part of the Research Topic Vitamin D: From Pathophysiology to Clinical Impact Volume II View all 12 articles

Comparative Analysis of COVID-19 Responses in Japan and Africa: Diet, Phytochemicals, Vitamin D, and Gut Microbiota in Reducing Mortality -A Systematic Review and Meta-Analysis

Provisionally accepted
Kazuki Santa Kazuki Santa 1Raita Tamaki Raita Tamaki 2*Kenji Watanabe Kenji Watanabe 3Isao Nagaoka Isao Nagaoka 4
  • 1 Juntendo University, Faculty of Medical Science, Urayasu, Japan
  • 2 Nagasaki University, Nagasaki, Nagasaki, Japan
  • 3 Yokohama University of Pharmacy, Yokohama, Japan
  • 4 Juntendo University, Bunkyō, Tōkyō, Japan

The final, formatted version of the article will be published soon.

    Background: As the novel coronavirus disease 2019 (COVID-19) pandemic subsides, the clinical sequelae are becoming more problematic. Interestingly, the statistical data indicate that Africa has experienced the lowest number of cases and deaths, with an unexpected phenomenon where the number of deaths from COVID-19 has not increased significantly. Several studies have investigated the relationship between diet and coronavirus. However, no systematic review/meta-analysis has conclusively linked diet (phytochemicals and vitamin D) and the gut microbiota in the context of COVID-19. Methods: This study examined the responses to COVID-19 in Japan and Africa, formulating the following hypotheses: 1) a healthy diet is effective against COVID-19, 2) blood vitamin D levels are associated with COVID-19 mortality, and 3) COVID-19 is associated with the gut microbiota. To investigate these hypotheses, a keyword search was conducted using PubMed, and each hypothesis was tested. Results: This study found that a healthy diet, particularly rich in phytochemicals such as polyphenols and flavonoids, is effective against COVID-19. An association was detected between blood vitamin D levels and COVID-19 mortality. The gut microbiota was linked to COVID-19 and its amelioration. These findings may have significant implications for not only understanding COVID-19 but also future prevention of pneumonia.

    Keywords: COVID-19, phytochemicals, Polyphenols, Flavonoids, Vitamin D, Gut Microbiota, Japan, Africa

    Received: 16 Jul 2024; Accepted: 13 Aug 2024.

    Copyright: © 2024 Santa, Tamaki, Watanabe and Nagaoka. This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.

    * Correspondence: Raita Tamaki, Nagasaki University, Nagasaki, 852-8521, Nagasaki, Japan

    Disclaimer: All claims expressed in this article are solely those of the authors and do not necessarily represent those of their affiliated organizations, or those of the publisher, the editors and the reviewers. Any product that may be evaluated in this article or claim that may be made by its manufacturer is not guaranteed or endorsed by the publisher.