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

Abstract

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.

Keywords:

• Pyrroloquinoline quinone disodium salt
• cognitive function
• cognitrax
• forgetfulness
• mini-mental state examination
• memory
• attention
• judgment
• cognitive flexibility

Acknowledgments

We would like to thank everyone who cooperated with this study, the participants, Akanuma Surgery Clinic, LSI Sapporo Clinic, Kyowa Trial Co., Ltd., and the staff of each medical institution. We thank DB and our group members at Ryusendo Co., Ltd. for their technical support and valuable discussions.

Disclosure statement

YS, MT, RT, and HM are employees of Ryusendo Co., Ltd., the study sponsor. DB and MB served as an independent consultant. MA is the resident investigator. Ryusendo provided the research funds to Kyowa Trial Co., Ltd. MA received a research grant from Kyowa Trial, and have no conflicts of interest to declare. YS, MT, RT, HM, MB and DB were not involved in the interpretation of results and did not influence the outcomes at any stage of the clinical trial. All authors have declared that they have no other conflict of interest.

Additional information

Funding

This study was partially funded by Ryusendo Co., Ltd., Japan.