Beneficial effect of Juncus effusus extract powder enriched with dehydroeffusol on the cognitive and dexterous performance of elderly people: A randomized, double-blind, placebo-controlled, parallel-group study.

On the basis of the evidence that dehydroeffusol prevents human amyloid-β-induced memory deficit and neurodegeneration in mice, here we tested the effect of a Juncus effusus extract powder enriched with dehydroeffusol on the cognitive and dexterous performance of elderly people. A randomized, double-blind, placebo-controlled, parallel-group study was conducted in 41 participants (averaged age: 69 years) randomly divided into test and placebo groups who received a test tablet and a placebo tablet, respectively, once a day for 24 weeks. Changes in cognitive function were assessed using the Five-Cog test 24 weeks after the start of intake. The task scores of the test group were significantly higher in the clue recall and clock-drawing tasks than in the placebo group, suggesting that intake of J. effusus extract powder may improve the cognitive function of elderly people. Moreover, the task score of the test group was significantly higher for the assembly task in the dexterity test than the placebo group, suggesting that intake of J. effusus extract powder may improve the dexterous movement of elderly people. No adverse events were clinically observed during the study. The present study first suggests that intake of J. effusus extract powder enriched with dehydroeffusol is of benefit to the cognitive and dexterous performance of elderly people.