2.2. Study Design and Participants
This study was conducted in Kunitachi-shi, Tokyo, from August to December 2021 as a double-blind, randomized, crossover, placebo-controlled study. The study protocol was registered at the UMIN (University Hospital Medical Information Network) Clinical Trials Registry (ID: UMIN000044852). The study comprised a 3-week pre-intervention period, a first 4-week intervention period, a 4-week washout period, and a second 4-week intervention period (