Study design
The study was conducted at KSO Inc. (Tokyo, Japan) from August to December 2021, under the supervision of Iwama Y. as the principal investigator with support from a project team composed of a doctor, a clinical laboratory technician, and a nutritionist. This 12-week, randomized, double-blind, placebo-controlled, parallel-group study divided the participants into the placebo and choline groups by the block-randomization method.The Cognitrax test [There were no dropouts during the study period, but five participants were excluded due to a substantial change in the living environment during the study period, a violation of study limitations, and a lack of reliability. One participant could not take the 12-weeks test on that day due to illness, and only a safety evaluation was conducted six days later. Furthermore, 14 subjects were excluded because they had 10% or more changes in the clinical test that have been reported to be associated with cognitive function [Flow chart