4. Discussion
chronic fatigue
This study aimed to test whether 12 weeks’ 6-MSITC intervention has positive effects on cognitive performances in healthy older adults. We found two main findings. First, the 6-MSITC intervention improved working memory capacity as measured by DS-B compared to the placebo group. Second, the 6-MSITC intervention improved episodic memory performances as measured by LM and FSM. These findings support our first hypothesis. However, contrary to our second hypothesis, we did not find any significant improvements in inhibition. These findings suggest that the 12 weeks’ 6-MSITC intake selectively enhances working and episodic memory functions in healthy older adults.In this study, working memory performances, as measured by DS-B, were improved after the 12 weeks’ 6-MSITC intake compared to the placebo intake. This result is consistent with previous studies using Sulforaphane [The second finding is that the 12 weeks’ 6-MSITC intake improved episodic memory performances, as measured by LM and FSN, in healthy older adults. This finding is consistent with a previous patient study using 6-MSITC in middle-aged patients with chronic fatigue [In contrast to the third and fourth hypotheses, there are no significant changes in the inhibition and processing speed performances after the 6-MSITC intake in older adults. This is inconsistent with a previous study showing a beneficial effect of 6-MSITC on inhibition performance [It is important to consider a potential mechanism of the improvements in memory functions after 6-MSITC intake. Previous studies have demonstrated that 6-MSITC has anti-oxidant and anti-inflammatory functions [This study has some limitations. First, we did not measure any biomarkers of anti-oxidants or anti-inflammatories. To understand the biological mechanism of the benefit of 6-MSITC, it is important to investigate a change in the biomarkers before and after intervention periods. Second, we recruited only healthy older adults. To generalize the current findings, further investigation is needed on whether 6-MSITC would improve cognitive functions in young adults. Third, the number of female participants was larger than that of the male participants in this study, even though we recruited participants from the public using advertisements. We used sex as the covariate in all analyses. Therefore, the effect of sex would be reduced in this study. However, it is important to perform RCTs with a 1:1 sex ratio in future studies.