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Article History

Received: 14 August 2025

Accepted: 18 February 2026

First Online: 28 February 2026

Declarations

:

: The ‘Sukoyaka Health Survey’ was conducted following the ethical principles of the Declaration of Helsinki (revised by the World Medical Association Fortaleza General Assembly in October 2013) and in compliance with the Ethical Guidelines for Medical Research for Persons (revised by the Ministry of Education, Culture, Sports, Science, and Technology and the Ministry of Health, Labour and Welfare on 28 February 2017). Written informed consent was obtained from all participants. This study was approved the feasibility of the clinical trials and their ethical and scientific validity by the Institutional Review Boards of the National Institutes of Biomedical Innovation, Health, and Nutrition (approval number: 2023-003), of Hokkaido Information University (approval number: 2019-04), of Kyoto University (approval number: R2445), of Miyazaki University (approval number: O-0724), and of Nagasaki University (approval number: 418). The participants were registered after providing written informed consent and participated in the summer and autumn–winter of a year.

: Not applicable.

: The authors declare no competing interests.