Glycine Supplementation Improves Cognitive Performance in Mexican Older Adults (Glycine)

June 8, 2026 updated by: Brenda Sarahí Beristain Lujano

The purpose of this study was to evaluate the effects of daily glycine supplementation on metabolic health and cognitive performance in older adults. Over a period of six months, participants received 1,000 mg of glycine per day to determine if this amino acid could improve markers of insulin resistance, glucose metabolism, and cognitive functions such as memory and executive tasks.

The research aimed to identify whether this nutritional intervention provides a safe and effective strategy to support healthy aging, focusing on the link between metabolic balance and brain health in the elderly population.

Study Overview

Status

Completed

Conditions

Intervention / Treatment

Detailed Description

A 6-month longitudinal study was conducted, featuring a glycine supplementation phase followed by a dietary maintenance period. Cognitive assessments and serum BDNF levels were monitored at baseline, 3 months (T3), and 6 months (T6). Which included the evaluation of fasting glucose, insulin levels, insulin resistance indices, and specific metabolic biomarkers. Concurrently, cognitive functions were evaluated utilizing standardized neuropsychological instruments to measure changes in memory, attention, and executive function. Linear Mixed-Effects Models (LMM) were used to analyze temporal trajectories.

Study Type

Interventional

Enrollment (Actual)

59

Phase

  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Locations

  • Mexico
    • State of Mexico
      • México, State of Mexico, Mexico, 01710
        • Escuela Superior de Medicina

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

Yes

Description

Inclusion Criteria:

  • Individuals across all nutritional statuses according to Body Mass Index (BMI), under-weight, normal weight, overweight, and obesity

Exclusion Criteria:

  • Clinically relevant comorbidities (requiring patient hospitalization or a diagnosis of any infectious/contagious disease), consumption of polyphenol-based supplements or herbal blends within the two weeks prior to the study and mental incapacity, lack of willingness, or language barriers that prevent adequate understanding or co-operation

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Supportive Care
  • Allocation: N/A
  • Interventional Model: Single Group Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm
Intervention / Treatment
Experimental: Glycine group
Participants received an oral daily dose of 1,000 mg of glycine for a duration of 6 months to evaluate metabolic and cognitive outcomes.
Dietary supplement: Glycine
Oral supplementation of glycine at a dose of 1,000 mg per day, administered daily over a 6-month period.

What is the study measuring?

Primary Outcome Measures

Outcome Measure
Measure Description
Time Frame
Brain-Derived Neurotrophic Factor (BDNF) levels
Time Frame: Baseline (T0), 3 months (T3) and 6 months (T6)
Evaluated the effects of glycine supplementation on cognitive performance, as meas-ured by the MMSE and MoCA scales, and its correlation with serum Brain-Derived Neurotrophic Factor (BDNF) levels in older adults.
Baseline (T0), 3 months (T3) and 6 months (T6)

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Brenda Sarahí Beristain Lujano

Collaborators

National Polytechnic Institute, Mexico
Instituto de Seguridad y Servicios Sociales de los Trabajadores del Estado

Investigators

  • Principal Investigator: Brenda Sarahí BS Beristain Lujano, MSc, Escuela Superior de Medicina IPN

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

December 1, 2024

Primary Completion (Actual)

June 1, 2025

Study Completion (Actual)

December 1, 2025

Study Registration Dates

First Submitted

June 8, 2026

First Submitted That Met QC Criteria

June 8, 2026

First Posted (Actual)

June 11, 2026

Study Record Updates

Last Update Posted (Actual)

June 11, 2026

Last Update Submitted That Met QC Criteria

June 8, 2026

Last Verified

June 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

  • HGDFF/DIR/CEI/232/2024

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data will not be shared to protect the privacy and confidentiality of the participants, in accordance with the informed consent and the guidelines of the Institutional Review Board (IRB).

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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