The goal of this randomized controlled double-blind parallel-group interventional trial is to evaluate the effects of dietary supplementation with molecular hydrogen and pyrroloquinoline quinone in elderly. The main questions it aims to answer are: (1) whether the supplementation affects biomarkers of mitochondrial function in serum, and (2) whether the supplementation affects cognition and brain metabolism. The participants will be subjected to take the dietary supplement during 6 weeks.

Inclusion Criteria:

• Age > 65 years
• MMSE scores ranged from 23-27
• Informed consent signed

Exclusion Criteria:

• Take part in exercise on a regular basis
• Severe chronic disease and acute injuries
• History of dietary supplement use during the past 4weeks
• No consent to randomization
• Participation in other studies

Data obtained through this study may be provided to qualified researchers with academic interest in age-related mild cognitive impairment. Data will be coded, with no PHI included. Approval of the request and execution of all applicable agreements are prerequisites to the sharing of data with the requesting party.

Data requests can be submitted starting 9 months after article publication and the data will be made accessible for up to 24 months. Extensions will be considered on a case-by-case basis.