Effect of Dietary Pyrroloquinoline Quinone Disodium Salt on Cognitive Function in Healthy Volunteers: A Randomized, Double-Blind, Placebo-Controlled, Parallel-Group Study

Background Cognitive dysfunctions are increasing alarmingly around the world, and researchers are exploring preventive measures for improving brain performance. Pyrroloquinoline quinone (PQQ), a naturally occurring coenzyme in foods, exhibits potent antioxidant activity, and improves diverse functions which include mitochondrial activation, growth, repair, protection of nerve cells by increased expression of nerve growth factor (NGF) and NGF receptors; and suppression of fibril formation and aggregation of amyloid β.Objective This randomized, double-blind, placebo-controlled, parallel-group clinical investigation (RCT) evaluated the efficacy and safety of PQQ disodium salt powder (mnemoPQQ®) for improved cognitive function after 12 weeks of supplementation in healthy Japanese male and female (age 40 to <80 Y). Methods 64 healthy subjects were randomly assigned to receive either mnemoPQQ® (PQQ disodium salt: 21.5 mg/day) or a placebo over a period of 12 weeks. The efficacy of mnemoPQQ® on cognitive performance (memory, attention, judgment, and cognitive flexibility) was examined using Cognitrax as the primary outcome (primary endpoint), and forgetfulness questionnaire (DECO: Deterioration Cognitive Observee) and Mini-Mental State Examination-Japanese (MMSE-J) as the secondary outcome (secondary endpoint).Results A total of 58 subjects (placebo = 31; Age = 70.91 ± 3.06 Y; mnemoPQQ® group = 27; Age = 72.10 ± 3.77 Y) completed the study over a period of 12 weeks of supplementation. Significant improvements were observed on the Cognitrax’s cognitive function domain score on “composite memory”, “verbal memory”, “reaction time”, “complex attention”, “cognitive flexibility”, “executive function”, and “motor speed” in the mnemoPQQ® group as compared to the placebo group. The DECO and the MMSE-J scores were also significantly improved in the mnemoPQQ® group. No adverse events were observed.Conclusions Study demonstrates that supplementation of PQQ disodium salt is useful in improving memory, attention, judgment, and cognitive function, in middle-aged to elderly population, who feel they have become more forgetful because of aging.