2.1. Study Design of Trial 1
memory complaints, dementia
A randomized, double-blind, placebo-controlled, parallel-group trial was designed to perform an exploratory evaluation of the effect of supplementation with LCPUFAs + LZ on memory function in healthy older Japanese individuals with memory complaints without dementia. This trial was conducted between April 2019 and February 2020 at a medical institution in Meguro-ku, Tokyo, Japan. A total of 776 participants were recruited from Tokyo and neighboring regions, of whom 120 were enrolled and randomly allocated to three groups: (1) a placebo group, receiving a placebo as a food supplement; (2) an LCPUFAs + X group, receiving a food supplement consisting of LCPUFAs (containing 120 mg ARA, 300 mg DHA, and 100 mg EPA per day) combined with compound X (whose contents are not shown because this compound is not the subject of this study); (3) an LCPUFAs + LZ group, receiving a food supplement consisting of LCPUFAs (containing 120 mg ARA, 300 mg DHA, and 100 mg EPA per day) combined with LZ (containing 10 mg lutein and 2 mg zeaxanthin per day). The intervention period was set at 24 weeks, based on previous studies that evaluated memory function using food components and considering that the potential for efficacy could be determined after less than 24 weeks of consumption [