The Acute Effects of Specialty Coffee on Cognitive Function in People With Type 2 Diabetes

February 11, 2026 updated by: Daniel Lamport, University of Reading

The Effects of Drinking Specialty Coffee on Cognition in People With Type 2 Diabetes

Coffee has been found to have beneficial effects on cognitive function and blood sugar control. Benefits include reduced risk of cognitive decline and improved performance on cognitive tests, as well as reduced risk of diabetes and improved blood sugar control in people with diabetes, a population that is at a higher risk of cognitive decline. These effects have been observed for both caffeinated and decaffeinated coffee, and have been associated with the polyphenol chlorogenic acid (CGA). This polyphenol has been found to be more bioavailable in certain coffees, known as "speciality coffee" as defined by the Specialty Coffee Association of America, depending on agriculture, roasting, and brewing method.

This current project will bring together these previous findings to explore the effects of specialty coffee on cognitive function in people with type 2 diabetes through a repeated measures trial with two conditions: a high CGA specialty coffee group and a conventional coffee control group. Participants will consume each beverage 1 week apart and will be tested before consumption, 5 hours after consumption, and 24 hours after consumption based on findings that CGA metabolism takes up to 36 hours. At the beginning and the end of each condition participants will undertake a cognitive assessment online using the Gorilla platform, and a series of questionnaires relating to health and mood measures (details in procedure).

In regard to key ethical issues, all participants will be coffee consumers therefore participants will be accustomed to consuming coffee and no adverse events are expected. The quantities of coffee to be consumed do not exceed the recommended daily intake of caffeine. The study will not impact on the participants ongoing management of their type 2 diabetes. Participants will be free to withdraw from the study any point without giving reason.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Completed

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Detailed Description

Following recruitment, interested participants will undertake an online screening session with the experimenter to check the inclusion and exclusion criteria (see section 3). Following this, study procedures will be explained in full by the experimenter and the participants will receive the information sheet (by email) and complete the consent form online. At this point, demographic information and chronic mood measures (BDI and GAD-7) will be collected. At the screening session participants will also undertake a practice version of the online cognitive tests, acute mood measure questionnaires, and an online 24 hour diet recall (ASA24) for familiarisation.

The cognitive tests will include digit span text entry, the digit symbol substitution task, Corsi blocks, and an auditory verbal learning test (AVLT). The standardised acute mood measures include the PANAS (outcome measures Positive and Negative Affect) and the Bond-Lader questionnaire (outcome measures alertness, attentiveness, and calmness). These will be adapted for online completion using the Gorilla platform. If able, participants will also self-report the following data relating to their glucose control and cardiovascular health to help characterise the sample: lipid panel (total cholesterol, HDL, LDL, and triglycerides) and HbA1C. Participants will have access this data from their routine type 2 diabetes consultations.

On test days, participants will log onto a video conference to meet with the researcher. They will complete the ASA24, cognitive battery, and acute mood measure questionnaires. Then participants will consume the provided coffee within 30 minutes. Participants will have either collected this coffee or have it posted to them alongside brewing equipment, standardised instructions for preparing, and a video demonstrating how to brew the coffee and use the equipment. Patients will log off the video call and will log back on 5 hours after finishing their coffee to undertake the cognitive battery and acute mood measures. No other coffee consumption is permitted during this time and participants will be instructed to consume a lunch low in CGA guided by a list of foods to avoid. They will log back on 24 hours after finishing their coffee to complete the cognitive battery and acute mood measures for the third and final time. For the third time point, participants will be instructed to consume the same breakfast and any coffee they had prior to meeting with the researcher at the first time point; coffee will be permitted in this instance to avoid withdrawal.

Upon completing the intervention, participants will be posed questions to explore attitudes about coffee drinking and blood sugar management.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Actual)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
40

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • 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

  • United States
    • California
      • Berkeley, California, United States, 94720
        • Berkeley

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

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Age 30 years or more
  • Formal diagnosis of Type 2 Diabetes for 1 year or more
  • Current coffee drinkers, 4 or fewer cups daily (a cup is 8 oz)

Exclusion Criteria:

  • Consuming on average more than 5 cups of coffee daily
  • Regularly consuming specialty coffee (participants will be provided with a list of these coffees)

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: Basic Science
  • Allocation: Randomized
  • Interventional Model: Crossover Assignment
  • Masking: Single

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Low Polyphenol coffee
Participants will be provided with a conventional, low CGA coffee to brew and consume which contains less CGA than the experimental arm.
Other: Coffee
12 ounces of coffee will be consumed
Experimental: High Polyphenol coffee
Participants will be provided with a single origin, CGA rich specialty coffee as graded by the Specialty Coffee Association of America's Q-grading system to brew and consume
Other: Coffee
12 ounces of coffee will be consumed

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Short term Memory
Time Frame: 0 hours
The Rey Auditory Verbal Learning Test (RAVLT) will present two lists of 15 words each, which will be played via audio recording after which participants will be asked to recite as many words as they can remember.
0 hours
Short term Memory
Time Frame: 0 hours
The Digit Span Forward Task will show a series of numbers in a specific order which participants will be asked to type out in the order shown
0 hours
Short term Memory
Time Frame: 0 hours
The Corsi Block Tapping task will present participants with a screen of blocks that light up in a sequence which participants will have to remember and tap the blocks in the order shown; the sequence lengthens or shortens based on participants performance.
0 hours
Processing Speed
Time Frame: 0 hours
A computerised version of the Digit Symbol Substitution Test (DSST) will be used to assess processing speed. Participants will be given a legend with numbers corresponding to symbols, then presented with a specific pair of number/symbol. They will then determine if that pair is a match or a mismatch, and respond accordingly. They will be measured for speed and accuracy.
0 hours
Processing Speed
Time Frame: 5 hours
A computerised version of the Digit Symbol Substitution Test (DSST) will be used to assess processing speed. Participants will be given a legend with numbers corresponding to symbols, then presented with a specific pair of number/symbol. They will then determine if that pair is a match or a mismatch, and respond accordingly. They will be measured for speed and accuracy.
5 hours
Processing Speed
Time Frame: 24 hours
A computerised version of the Digit Symbol Substitution Test (DSST) will be used to assess processing speed. Participants will be given a legend with numbers corresponding to symbols, then presented with a specific pair of number/symbol. They will then determine if that pair is a match or a mismatch, and respond accordingly. They will be measured for speed and accuracy.
24 hours
Long Term Memory
Time Frame: 0 hours
Long term memory will be assessed using the Rey Auditory Verbal Learning Test (RAVLT), where participants will be asked to recall as many words as possible from the previous two lists words heard earlier.
0 hours
Long Term Memory
Time Frame: 5 hours
Long term memory will be assessed using the Rey Auditory Verbal Learning Test (RAVLT), where participants will be asked to recall as many words as possible from the previous two lists words heard earlier.
5 hours
Long Term Memory
Time Frame: 24 hours
Long term memory will be assessed using the Rey Auditory Verbal Learning Test (RAVLT), where participants will be asked to recall as many words as possible from the previous two lists words heard earlier.
24 hours
Source Monitoring
Time Frame: 0 hours
Source monitoring will be assessed using a modified version of the Rey Auditory Verbal Learning Test (RAVLT) where a third "distractor" list will be presented, after which participants will be asked to recognize if a word is one heard in the original two lists, or a new word. If participants respond the former, they will then be asked to identify which list they heard the word from.
0 hours
Source Monitoring
Time Frame: 5 hours
Source monitoring will be assessed using a modified version of the Rey Auditory Verbal Learning Test (RAVLT) where a third "distractor" list will be presented, after which participants will be asked to recognize if a word is one heard in the original two lists, or a new word. If participants respond the former, they will then be asked to identify which list they heard the word from.
5 hours
Source Monitoring
Time Frame: 24 hours
Source monitoring will be assessed using a modified version of the Rey Auditory Verbal Learning Test (RAVLT) where a third "distractor" list will be presented, after which participants will be asked to recognize if a word is one heard in the original two lists, or a new word. If participants respond the former, they will then be asked to identify which list they heard the word from.
24 hours
Short term Memory
Time Frame: 5 hours
The Rey Auditory Verbal Learning Test (RAVLT) will present two lists of 15 words each, which will be played via audio recording after which participants will be asked to recite as many words as they can remember.
5 hours
Short term Memory
Time Frame: 5 hours
The Corsi Block Tapping task will present participants with a screen of blocks that light up in a sequence which participants will have to remember and tap the blocks in the order shown; the sequence lengthens or shortens based on participants performance.
5 hours
Short term Memory
Time Frame: 5 hours
The Digit Span Forward Task will show a series of numbers in a specific order which participants will be asked to type out in the order shown
5 hours
Short term Memory
Time Frame: 24 hours
The Rey Auditory Verbal Learning Test (RAVLT) will present two lists of 15 words each, which will be played via audio recording after which participants will be asked to recite as many words as they can remember.
24 hours
Short term Memory
Time Frame: 24 hours
The Digit Span Forward Task will show a series of numbers in a specific order which participants will be asked to type out in the order shown
24 hours
Short term Memory
Time Frame: 24 hours
The Corsi Block Tapping task will present participants with a screen of blocks that light up in a sequence which participants will have to remember and tap the blocks in the order shown; the sequence lengthens or shortens based on participants performance.
24 hours

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Mood
Time Frame: 0 hours
Positive affect will be measured using the Positive and Negative Affect Schedule (PANAS). The ratings (a scale of 1-5) for the 10 positive items will be summed to get a Positive Affect (PA) score. Scores can range from 10 to 50, with higher scores indicated higher levels of PA
0 hours
Mood
Time Frame: 0 hours
Negative affect will be measured using the Positive and Negative Affect Schedule (PANAS). The ratings (a scale of 1-5) for the 10 negative items will be summed to get a Negative Affect (NA) score. Scores can range from 10 to 50, with higher scores indicated higher levels of PA
0 hours
Mood
Time Frame: 0 hours
Mood will be measured using the Bond-Lader Visual Analogue Scale (BL-VAS) where participants rate their mood by marking a continuous line between two extreme endpoints, typically ranging from "not at all" to "extremely." The values are averaged into three categories (alertness, contentedness, and calmness) and higher scores indicate higher experiencing of each category.
0 hours
Mood
Time Frame: 0 hours
Mood will be measured using the Immediate Mood Scaler (IMS), which captures current mood states using 7-point Likert scales. The total score is calculated by summing all 22 items, with higher scores indicating more negative mood states
0 hours
Mood
Time Frame: 5 hours
Positive affect will be measured using the Positive and Negative Affect Schedule (PANAS). The ratings (a scale of 1-5) for the 10 positive items will be summed to get a Positive Affect (PA) score. Scores can range from 10 to 50, with higher scores indicated higher levels of PA
5 hours
Mood
Time Frame: 5 hours
Negative affect will be measured using the Positive and Negative Affect Schedule (PANAS). The ratings (a scale of 1-5) for the 10 negative items will be summed to get a Negative Affect (NA) score. Scores can range from 10 to 50, with higher scores indicated higher levels of PA
5 hours
Mood
Time Frame: 5 hours
Mood will be measured using the Bond-Lader Visual Analogue Scale (BL-VAS) where participants rate their mood by marking a continuous line between two extreme endpoints, typically ranging from "not at all" to "extremely." The values are averaged into three categories (alertness, contentedness, and calmness) and higher scores indicate higher experiencing of each category.
5 hours
Mood
Time Frame: 5 hours
Mood will be measured using the Immediate Mood Scaler (IMS), which captures current mood states using 7-point Likert scales. The total score is calculated by summing all 22 items, with higher scores indicating more negative mood states
5 hours
Mood
Time Frame: 24 hours
Positive affect will be measured using the Positive and Negative Affect Schedule (PANAS). The ratings (a scale of 1-5) for the 10 positive items will be summed to get a Positive Affect (PA) score. Scores can range from 10 to 50, with higher scores indicated higher levels of PA
24 hours
Mood
Time Frame: 24 hours
Negative affect will be measured using the Positive and Negative Affect Schedule (PANAS). The ratings (a scale of 1-5) for the 10 negative items will be summed to get a Negative Affect (NA) score. Scores can range from 10 to 50, with higher scores indicated higher levels of PA
24 hours
Mood
Time Frame: 24 hours
Mood will be measured using the Bond-Lader Visual Analogue Scale (BL-VAS) where participants rate their mood by marking a continuous line between two extreme endpoints, typically ranging from "not at all" to "extremely." The values are averaged into three categories (alertness, contentedness, and calmness) and higher scores indicate higher experiencing of each category.
24 hours
Mood
Time Frame: 24 hours
Mood will be measured using the Immediate Mood Scaler (IMS), which captures current mood states using 7-point Likert scales. The total score is calculated by summing all 22 items, with higher scores indicating more negative mood states
24 hours

Collaborators and Investigators

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

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
University of Reading

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)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
November 9, 2023

Primary Completion (Actual)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
August 23, 2024

Study Completion (Actual)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
August 23, 2024

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
February 20, 2024

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 11, 2026

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
February 19, 2026

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
February 19, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
February 11, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
February 1, 2026

More Information

Terms related to this study

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • UReading Acute Coffee Diabetes

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

YES

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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