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Overweight (BMI > 25)NCT07883031

Effects of Yerba Mate Supplementation on Metabolic Health, Physical Function, and Cognition in Older Adults With Excess Adiposity

A study testing Yerba Mate in people with Overweight (BMI > 25) and Obesity & Overweight, run by University of North Alabama at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

The purpose of this study was to find out whether taking yerba mate, a plant-based supplement, could improve health in adults aged 60 years or older with excess body fat. Researchers examined how the body uses fat during walking, blood cholesterol levels, body composition, strength, mobility, thinking skills, and… Read more about this study

Who is it for?
Ages 60 years and older
Conditions the study is for
Overweight (BMI > 25), Obesity & Overweight
What is being tested?
Yerba Mate
Type of treatment
Pill or oral medicine
Could I receive a placebo?
Yes, some participants may receive a placebo
How many people
25 participants
Where
1 siteUnited States
Study dates
15 Nov 2025to 16 Jun 2026
Phase
Interventional
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 60 years and older
  • All sexes
  • No healthy volunteers
  • Adult, Older adult

Who may be able to join

  • Age 60 years or older.
  • Excess adiposity, defined by meeting at least two of the following criteria: body mass index ≥25 kg/m²; waist-to-hip ratio ≥0.90 for males or ≥0.85 for females; body fat percentage ≥25% for males or ≥35% for females.
  • Ability to walk independently on a treadmill for at least 10 minutes.
  • Ability to complete computerized cognitive assessments independently.
  • Stable medication use for at least 3 months.
  • Habitual caffeine intake below 300 mg/day.
  • Ability to provide written informed consent and comply with study procedures.

Who cannot join

  • Major uncontrolled chronic disease.
  • Diagnosed neurodegenerative disease or cognitive impairment, or Montreal Cognitive Assessment score below 18.
  • Diagnosed psychiatric disorder or recent initiation of psychotropic medication.
  • Mobility limitations preventing completion of treadmill testing.
  • Uncontrolled hypertension, insulin-treated diabetes, or clinically significant hepatic or renal disease.
  • Untreated sleep apnea or cardiac arrhythmias requiring antiarrhythmic therapy.
Show all 11Show fewer
  • Allergy to yerba mate or use of stimulant supplements.
  • Active smoking.
  • Antibiotic or probiotic use within the previous 3 months.
  • Vegan or vegetarian diet.
  • Physical activity exceeding 10 hours per week.

Trial locations and contacts

1 site in 1 country.

United States1 site
  • University of North Alabama

    Florence, Alabama, 35661

Other trials in United States

About this study

Official title: Multisystem Effects of Yerba Mate Supplementation on Physiological, Cognitive, and Molecular Health in Overweight Older Adults

The purpose of this study was to find out whether taking yerba mate, a plant-based supplement, could improve health in adults aged 60 years or older with excess body fat. Researchers examined how the body uses fat during walking, blood cholesterol levels, body composition, strength, mobility, thinking skills, and well-being. They also explored changes in inflammation, gene activity, and gut bacteria.

Participants took yerba mate capsules for six weeks and placebo capsules for six weeks, with a four-week break between the two periods. The placebo contained no yerba mate. The order was assigned by chance. Participants and the researchers conducting the tests did not know which capsules participants were taking during each period.

Participants completed blood tests, body measurements, walking tests, strength and mobility tests, thinking tasks, and questionnaires. Researchers compared the results from the yerba mate and placebo periods.

Read the detailed description

This randomized, double-blind, placebo-controlled crossover study evaluated the physiological and molecular effects of yerba mate supplementation in older adults with excess adiposity. The study included two 6-week supplementation periods separated by a 4-week washout. Participants received yerba mate extract during one period and placebo during the other, in a randomized order. The crossover design allowed participants to serve as their own controls.

Clinical, functional, and cognitive assessments were conducted before and after each supplementation period. Laboratory testing included fasting blood collection, body composition assessment using dual-energy X-ray absorptiometry, and indirect calorimetry during walking at standardized treadmill speeds to evaluate whole-body fat oxidation and walking economy. Physical function, muscle strength, cognitive performance, and self-reported health and well-being were also assessed.

Additional analyses examined circulating inflammatory markers, gene expression, and gut microbiota composition using samples collected at the end of each supplementation period. These analyses explored biological pathways potentially associated with the physiological responses to supplementation. Molecular analyses were performed in participant subsets according to sample availability.

Clinical outcomes were compared between supplementation conditions using measurements collected before and after each period. Inflammatory markers, gene expression, and gut microbiota outcomes were compared between conditions using end-of-period measurements.

Being tested
Yerba Mate, Placebo
Keywords
Yerba mate, Ilex paraguariensis, older adults, overweight, gut microbiota, cognitive function, fat oxidation, inflammation, nutrigenomics
Medical subject headings
Overweight, Obesity, Inflammation

What participants receive

What participants receive. In a randomised study each person is assigned to one group by chance.

  • Yerba MateDietary supplement

    Yerba mate (Ilex paraguariensis) extract administered orally as six 500-mg capsules daily (3,000 mg/day) for 6 weeks. The extract had a 6:1 extraction ratio and was standardized to 37-40% chlorogenic acids and no more than 2% caffeine.

  • PlaceboDietary supplement

    Also called Food starch

    Placebo administered orally as six capsules daily for 6 weeks, following the same dosing schedule as the yerba mate intervention.

Study groups in NCT07883031
Study groupRoleWhat they receive
Yerba MateActive comparatorParticipants received yerba mate extract (six 500-mg capsules daily; 3,000 mg/day) for 6 weeks
Receives: Dietary Supplement: Yerba Mate
PlaceboPlacebo comparatorParticipants received placebo for 6 weeks, followed by a 4-week washout period
Receives: Dietary Supplement: Placebo

What is being measured

The primary outcome is the main question the study is designed to answer.

  1. Fat Oxidation During Walking

    Whole-body fat oxidation rate (g/min), calculated from oxygen uptake and carbon dioxide production measured by indirect calorimetry during standardized treadmill walking.

    Measured: Before and after each 6-week supplementation period.

  2. Walking Economy

    Oxygen cost of walking, expressed in milliliters of oxygen per kilogram of body mass per meter walked. The value is calculated by dividing mass-specific oxygen uptake in mL/kg/min by walking speed in meters per minute. Lower values indicate better walking economy.

    Measured: Before and after each 6-week supplementation period.

  3. Fasting Triglycerides

    Fasting triglyceride concentration (mg/dL), assessed using the Cholestech LDX system.

    Measured: Before and after each 6-week supplementation period.

  4. Psychomotor Vigilance Task Reaction Time

    Reaction time, expressed in milliseconds, during the computerized Psychomotor Vigilance Task, which assesses sustained attention and vigilance. Shorter reaction times indicate faster responses.

    Measured: Before and after each 6-week supplementation period.

  5. Transcript Expression Fold Change

    Expression of protein-coding and noncoding transcripts assessed using the Affymetrix Clariom D human microarray. Differences between yerba mate and placebo supplementation conditions are expressed as fold changes in transcript expression, with results reported individually for each transcript.

    Measured: At the end of each 6-week supplementation period.

  6. Eriksen Flanker Task Incongruent-Trial Reaction Time

    Reaction time, expressed in milliseconds, during incongruent trials of the computerized Eriksen Flanker Task, which assesses inhibitory control. Shorter reaction times indicate faster performance.

    Measured: Before and after each 6-week supplementation period.

  7. Task-Switching Reaction Time

    Reaction time, expressed in milliseconds, during the computerized task-switching task, which assesses cognitive flexibility. Shorter reaction times indicate faster performance.

    Measured: Before and after each 6-week supplementation period.

Secondary outcomes (16)
  1. Fasting Blood Glucose

    Fasting blood glucose concentration (mg/dL), measured using the Cholestech LDX system.

    Measured: Before and after each 6-week supplementation period.

  2. Blood Pressure

    Resting diastolic blood pressure (mmHg), measured using an automated upper-arm monitor after 5 minutes of seated rest.

    Measured: Before and after each 6-week supplementation period.

  3. Interleukin-6 Relative Abundance Fold Change

    Relative plasma interleukin-6 abundance assessed using a cytokine antibody array. Results are expressed as the dimensionless ratio of normalized signal intensity after yerba mate to that after placebo. A ratio of 1 indicates equal abundance between conditions; values above 1 indicate higher abundance after yerba mate, and values below 1 indicate lower abundance compared with placebo.

    Measured: After each 6-week supplementation period.

  4. Relative Abundance of Gut Bacterial Taxa

    Relative abundance of bacterial taxa in stool samples assessed by sequencing the V3-V4 region of the bacterial 16S ribosomal RNA gene. Results are expressed as percentages of bacterial sequencing reads assigned to each taxon, ranging from 0% to 100%. Higher percentages indicate greater relative representation of the taxon in the sample. Taxa are reported individually and compared between yerba mate and placebo supplementation conditions.

    Measured: At the end of a 6-week supplementation period.

  5. Tumor Necrosis Factor Alpha Relative Abundance Fold Change

    Relative plasma tumor necrosis factor alpha abundance assessed using a cytokine antibody array. Results are expressed as the dimensionless ratio of normalized signal intensity after yerba mate to that after placebo. A ratio of 1 indicates equal abundance between conditions; values above 1 indicate higher abundance after yerba mate, and values below 1 indicate lower abundance compared with placebo.

    Measured: After each 6-week supplementation period.

  6. Interleukin-1 Beta Relative Abundance Fold Change

    Relative plasma interleukin-1 beta abundance assessed using a cytokine antibody array. Results are expressed as the dimensionless ratio of normalized signal intensity after yerba mate to that after placebo. A ratio of 1 indicates equal abundance between conditions; values above 1 indicate higher abundance after yerba mate, and values below 1 indicate lower abundance compared with placebo.

    Measured: After each 6-week supplementation period.

  7. Interleukin-10 Relative Abundance Fold Change

    Relative plasma interleukin-10 abundance assessed using a cytokine antibody array. Results are expressed as the dimensionless ratio of normalized signal intensity after yerba mate to that after placebo. A ratio of 1 indicates equal abundance between conditions; values above 1 indicate higher abundance after yerba mate, and values below 1 indicate lower abundance compared with placebo.

    Measured: After each 6-week supplementation period.

  8. Interferon Gamma Relative Abundance Fold Change

    Relative plasma interferon gamma abundance assessed using a cytokine antibody array. Results are expressed as the dimensionless ratio of normalized signal intensity after yerba mate to that after placebo. A ratio of 1 indicates equal abundance between conditions; values above 1 indicate higher abundance after yerba mate, and values below 1 indicate lower abundance compared with placebo.

    Measured: After each 6-week supplementation period.

  9. Monocyte Chemoattractant Protein-1 Relative Abundance Fold Change

    Relative plasma monocyte chemoattractant protein-1, also known as C-C motif chemokine ligand 2, abundance assessed using a cytokine antibody array. Results are expressed as the dimensionless ratio of normalized signal intensity after yerba mate to that after placebo. A ratio of 1 indicates equal abundance between conditions; values above 1 indicate higher abundance after yerba mate, and values below 1 indicate lower abundance compared with placebo.

    Measured: After each 6-week supplementation period.

  10. Cognitive Failures Questionnaire Total Score

    Perceived cognitive failures assessed using the 25-item Cognitive Failures Questionnaire. Each item is scored from 0 to 4, yielding a total score from 0 to 100. Higher scores indicate more frequent cognitive failures and a worse outcome.

    Measured: After each 6-week supplementation period.

  11. World Health Organization-Five Well-Being Index Score

    Psychological well-being assessed using the World Health Organization-Five Well-Being Index. Five items are scored from 0 to 5. The summed score is multiplied by four to obtain a final score from 0 to 100. Higher scores indicate better psychological well-being.

    Measured: After each 6-week supplementation period.

  12. 15-Item Geriatric Depression Scale Total Score

    Depressive symptoms assessed using the 15-item Geriatric Depression Scale. The total score ranges from 0 to 15. Higher scores indicate more depressive symptoms and a worse outcome.

    Measured: After each 6-week supplementation period.

  13. Generalized Anxiety Disorder 7-Item Scale Total Score

    Anxiety symptoms assessed using the Generalized Anxiety Disorder 7-Item Scale. Each item is scored from 0 to 3, yielding a total score from 0 to 21. Higher scores indicate greater anxiety symptom severity and a worse outcome.

    Measured: After each 6-week supplementation period.

  14. Pittsburgh Sleep Quality Index Global Score

    Sleep quality assessed using the Pittsburgh Sleep Quality Index. Seven component scores, each ranging from 0 to 3, are summed to obtain a global score from 0 to 21. Higher scores indicate poorer sleep quality and a worse outcome.

    Measured: After each 6-week supplementation period.

  15. Fatigue Severity Scale Total Score

    Fatigue severity and its impact on daily activities assessed using the nine-item Fatigue Severity Scale. Each item is scored from 1 to 7, yielding a total score from 9 to 63. Higher scores indicate greater fatigue and a worse outcome.

    Measured: After each 6-week supplementation period.

  16. Brief Resilience Scale Mean Score

    Resilience assessed using the six-item Brief Resilience Scale. Items 2, 4, and 6 are reverse-scored, and the six item scores are averaged. The mean score ranges from 1 to 5. Higher scores indicate greater resilience and a better outcome.

    Measured: After each 6-week supplementation period.

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted20 Oct 2026
  2. Study start15 Nov 2025
  3. Primary completion16 Jun 2026
  4. Study completion16 Jun 2026

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Interventional
Phase
Phase N/A
Primary purpose
Basic science
Allocation
Randomised
Intervention model
Crossover
Masking
Triple blind
Who is masked
Participant, Investigator, Outcomes assessor
Enrolment
25 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT07883031
Sponsor's protocol ID
2025-029
Status last verified
Oct 2026
First submitted
8 Oct 2026
Last updated
20 Oct 2026
Results posted
No
Data monitoring committee
No
FDA-regulated drug
No
FDA-regulated device
No
Individual data sharing
No: There is currently no plan to share individual participant data. Study findings will be disseminated through scientific publications and presentations using aggregate results.

Questions about this trial

What is this clinical trial studying?

A study testing Yerba Mate in people with Overweight (BMI > 25) and Obesity & Overweight, run by University of North Alabama at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 7 inclusion and 11 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 20 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. Some participants in this study may receive a placebo. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

What does the primary outcome measure?

Fat Oxidation During Walking (time frame: Before and after each 6-week supplementation period.). The study lists 7 primary outcomes in all. It is what the study was designed to measure, not a finding.

Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 20 Oct 2026.

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