Type 2 Diabetes MellitusNCT07233460
Effect of Using Bitter Melon, Blueberries and Cranberries on HbA1c and Diabetes Symptom Levels
A study testing Bitter Melon Group, Blueberry Group and Cranberry Group in people with Type 2 Diabetes Mellitus and Symptoms and Signs, run by Hatice Demirağ, Ph.D at 1 site in Turkey (Türkiye).
Trial summary
This double-blind, randomized controlled trial investigated the effect of bitter melon, blueberry, and cranberry powder extract use on glycemic control and diabetes symptom levels in individuals with T2DM. Read more about this study
- Who is it for?
- Ages 18 years and older
- Conditions the study is for
- Type 2 Diabetes Mellitus, Symptoms and Signs, Patient
- What is being tested?
- Bitter Melon Group, Blueberry Group and Cranberry Group
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 120 participants
- Where
- 1 siteTurkey (Türkiye)
- Study dates
- 6 Feb 2024to 15 May 2024
- 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 18 years and older
- All sexes
- No healthy volunteers
- Adult, Older adult
Who may be able to join
- Being 18 years of age or older,
- Volunteering to participate in the study,
- Being conscious and able to communicate,
- Having been diagnosed with T2DM at least 3 months prior and currently using oral antidiabetic medication,
- Be using one of the following powder extracts-bitter melon, blueberry, or cranberry-for the first time as a complementary treatment upon a physician's recommendation and be on the first day of use,
- Not taking any other medications that affect blood sugar,
Show all 9Show fewer
- No allergy to bitter melon, blueberry, or cranberry,
- Not engaging in exercise,
- Taking 10g of bitter melon, blueberry, or cranberry powder extract daily.
Who cannot join
- Not meeting the inclusion criteria, having a known psychological disorder,
- Having previously received complementary therapy for DM, or having hearing loss.
Trial locations and contacts
1 site in 1 country.
About this study
Official title: Effect of Use of Bitter Melon, Blueberry and Cranberry as Complementary Therapy on HbA1c and Diabetes Symptom Level in Individuals With Type 2 Diabetes Mellitus: Single-blind Randomized Controlled Study
This double-blind, randomized controlled trial investigated the effect of bitter melon, blueberry, and cranberry powder extract use on glycemic control and diabetes symptom levels in individuals with T2DM.
Read the detailed description
The increasing prevalence of Type 2 Diabetes Mellitus (T2DM) worldwide and the search for additional support to current treatments have increased interest in researching natural components such as bitter melon, blueberry, and cranberry, known for their antioxidant and hypoglycemic potential, as complementary therapies. This double-blind, randomized controlled trial investigated the effect of bitter melon, blueberry, and cranberry powder extract use on glycemic control and diabetes symptom levels in individuals with T2DM.
The study, conducted with four groups (bitter melon, blueberry, cranberry, and control), included 120 individuals diagnosed with T2DM. Individuals in the experimental group used 10g of powdered extract daily for 12 weeks, while those in the control group used nothing. The 'Patient Information Form' and 'Diabetes Symptoms Checklist Scale' were administered before the start of the study (pre-test/week 0) and at the end (post-test/week 12), and the venous blood value of the Hemoglobin A1c test (HbA1c) was measured.
In the experimental groups (bitter melon, blueberry, cranberry), after 12 weeks of treatment, statistically significant decreases were observed in HbA1c, the total score and all Subdimensions scores of the 'Diabetes Symptoms Checklist Scale', weight, and BMI compared to the control group; while in the control group, there was a significant increase in all parameters except HbA1c (p<0.05). Although there was no difference between the experimental (bitter melon, blueberry, cranberry) groups in the intergroup measurements, HbA1c, the total mean scores of the Diabetes Symptom Checklist Scale, weight, and BMI were found to be significantly lower than in the control group (p<0.05).
Bitter melon, blueberry, and cranberry powder extracts were found to be equally effective in reducing HbA1c, diabetes symptoms, weight, and BMI in T2DM patients. The lack of difference in efficacy between the three extracts in terms of glycemic and symptom levels suggests that these three natural products can be considered equivalent therapeutic options in the complementary treatment of T2DM.
- Conditions
- Type 2 Diabetes Mellitus, Symptoms and Signs, Patient
- Being tested
- Bitter Melon Group, Blueberry Group, Cranberry Group
- Keywords
- Type 2 Diabetes Mellitus, Complementary and alternative medicine, Symptoms and Signs, Cranberry, Bitter melon, Blueberry.
- Medical subject headings
- Diabetes Mellitus, Type 2, Signs and Symptoms
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Bitter Melon GroupOther
Patients who voluntarily used bitter melon powder extract continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks.
Blueberry GroupOther
Patients who voluntarily used bitter blueberry powder extract continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks.
Cranberry GroupOther
Patients who voluntarily used cranberry powder extract continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks.
| Study group | Role | What they receive |
|---|---|---|
| Bitter melon Group | Experimental | Before starting the study (pre-test/week 0), all group participants first completed the "Patient Information Form" and the "Diabetes Symptom Checklist Scale," and their HbA1c venous blood values were measured. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals in the three groups, and their HbA1c venous blood values were measured. In addition, telephone follow-up was conducted to determine whether the individuals had used the powdered extracts completely for 12 weeks. Receives: Other: Bitter Melon Group |
| Blueberry Group | Experimental | Before starting the study (pre-test/week 0), all group participants first completed the "Patient Information Form" and the "Diabetes Symptom Checklist Scale," and their HbA1c venous blood values were measured. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals in the three groups, and their HbA1c venous blood values were measured. In addition, telephone follow-up was conducted to determine whether the individuals had used the powdered extracts completely for 12 weeks. Receives: Other: Blueberry Group |
| Cranberry Group | Experimental | Before starting the study (pre-test/week 0), all group participants first completed the "Patient Information Form" and the "Diabetes Symptom Checklist Scale," and their HbA1c venous blood values were measured. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals in the three groups, and their HbA1c venous blood values were measured. In addition, telephone follow-up was conducted to determine whether the individuals had used the powdered extracts completely for 12 weeks. Receives: Other: Cranberry Group |
| Control Group | No intervention | Before starting the study (pre-test/week 0), all group participants first completed the "Patient Information Form" and the "Diabetes Symptom Checklist Scale," and their HbA1c venous blood values were measured. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals in the three groups, and their HbA1c venous blood values were measured. |
What is being measured
The primary outcome is the main question the study is designed to answer.
HbA1c
Unlike instant blood glucose values, HbA1c reliably reflects an individual's average blood sugar level over the past two to three months by measuring the amount of glucose bound to hemoglobin during the average lifespan of erythrocytes (approximately 120 days).
Before starting the study (pre-test/week 0) HbA1c venous blood values were measured. Patients who voluntarily used bitter melon, blueberry, or cranberry continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks. At the end of the study (post-test/12th week), the was administered again to individuals HbA1c venous blood values were measured.
Measured: 12 week
Diabetes Symptom Checklist Scale
The scale consists of a total of 34 items. These categories are: neurology (3, 11, 15, 21, 25, 34), psychology (1, 2, 4, 6, 17, 20), cardiology (5, 8, 9, 13, 24, 26, 29, 30), ophthalmology (10, 14, 22, 28), psychology/cognition (7, 19, 27, 31, 33), and hyperglycemia (12, 16, 23, 32) Subdimensionss. Responses on the scale are numbered from 0 to 5, with "0" meaning "none" and "5" meaning "extremely."
Before starting the study (pre-test/week 0), all group participants first completed "Diabetes Symptom Checklist Scale" were measured. Patients who voluntarily used bitter melon, blueberry, or cranberry continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals were measured.
Measured: 12 week
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted18 Nov 2025
- Study start6 Feb 2024
- Primary completion15 Feb 2024
- Study completion15 May 2024
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Type 2 Diabetes MellitusStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
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
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Model description
- As no reference could be made to any previous four-group study on the subject, and considering the small size of the city where the research would be conducted, it was decided to include a total of 120 individuals with T2DM in the study sample, with 30 individuals in each group (bitter melon group, blueberry group, cranberry group, and control group). However, considering reasons such as death, withdrawal from the study, or missing data, it was decided to increase the sample size by 10% to 132 individuals.
- Masking
- Double blind
- Who is masked
- Investigator, Outcomes assessor
- Enrolment
- 120 participants (actual)
Sponsor and investigators
- Lead sponsor
- Hatice Demirağ, Ph.D
- Sponsor type
- University, hospital or other
- Collaborators
- Karadeniz Technical University
- Responsible party
- Sponsor-investigator, Hatice Demirağ, Ph.D, Karadeniz Technical University
- Investigators
- Hatice Demirağ, Principal investigator, Study Principal Investigator Gümüşhane Universıty
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07233460
- Sponsor's protocol ID
- RCS05022024
- Status last verified
- Nov 2025
- First submitted
- 14 Nov 2025
- Last updated
- 21 Nov 2025
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Maybe I will decide later.
Study at a glance
From the registry record, last updated by the sponsor on 21 Nov 2025. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Effect of Use of Bitter Melon, Blueberry and Cranberry as Complementary Therapy on HbA1c and Diabetes Symptom Level in Individuals With Type 2 Diabetes Mellitus: Single-blind Randomized Controlled Study
- ClinicalTrials.gov ID
- NCT07233460
- Acronym / sponsor ID
- RCS05022024
- Conditions
- Type 2 Diabetes Mellitus, Symptoms and Signs, Patient
- Keywords
- Type 2 Diabetes Mellitus, Complementary and alternative medicine, Symptoms and Signs, Cranberry, Bitter melon, Blueberry.
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 120 participants (actual)
- Lead sponsor
- Hatice Demirağ, Ph.DUniversity, hospital or other
- Collaborators
- Karadeniz Technical University
- Study start
- 6 Feb 2024 (actual)
- Primary completion
- 15 Feb 2024 (actual)
- Study completion
- 15 May 2024 (actual)
- First posted
- 18 Nov 2025 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This double-blind, randomized controlled trial investigated the effect of bitter melon, blueberry, and cranberry powder extract use on glycemic control and diabetes symptom levels in individuals with T2DM.
Detailed description
The increasing prevalence of Type 2 Diabetes Mellitus (T2DM) worldwide and the search for additional support to current treatments have increased interest in researching natural components such as bitter melon, blueberry, and cranberry, known for their antioxidant and hypoglycemic potential, as complementary therapies. This double-blind, randomized controlled trial investigated the effect of bitter melon, blueberry, and cranberry powder extract use on glycemic control and diabetes symptom levels in individuals with T2DM.
The study, conducted with four groups (bitter melon, blueberry, cranberry, and control), included 120 individuals diagnosed with T2DM. Individuals in the experimental group used 10g of powdered extract daily for 12 weeks, while those in the control group used nothing. The 'Patient Information Form' and 'Diabetes Symptoms Checklist Scale' were administered before the start of the study (pre-test/week 0) and at the end (post-test/week 12), and the venous blood value of the Hemoglobin A1c test (HbA1c) was measured.
In the experimental groups (bitter melon, blueberry, cranberry), after 12 weeks of treatment, statistically significant decreases were observed in HbA1c, the total score and all Subdimensions scores of the 'Diabetes Symptoms Checklist Scale', weight, and BMI compared to the control group; while in the control group, there was a significant increase in all parameters except HbA1c (p<0.05). Although there was no difference between the experimental (bitter melon, blueberry, cranberry) groups in the intergroup measurements, HbA1c, the total mean scores of the Diabetes Symptom Checklist Scale, weight, and BMI were found to be significantly lower than in the control group (p<0.05).
Bitter melon, blueberry, and cranberry powder extracts were found to be equally effective in reducing HbA1c, diabetes symptoms, weight, and BMI in T2DM patients. The lack of difference in efficacy between the three extracts in terms of glycemic and symptom levels suggests that these three natural products can be considered equivalent therapeutic options in the complementary treatment of T2DM.
Study design
- Primary purpose
- Supportive care
- Allocation
- Randomised
- Intervention model
- Parallel groups
- Masking
- Double blind (investigator, outcomes assessor)
- Number of arms
- 4
- Model description
- As no reference could be made to any previous four-group study on the subject, and considering the small size of the city where the research would be conducted, it was decided to include a total of 120 individuals with T2DM in the study sample, with 30 individuals in each group (bitter melon group, blueberry group, cranberry group, and control group). However, considering reasons such as death, withdrawal from the study, or missing data, it was decided to increase the sample size by 10% to 132 individuals.
| Arm | Type | Receives |
|---|---|---|
| Bitter melon Group | Experimental | Other: Bitter Melon GroupBefore starting the study (pre-test/week 0), all group participants first completed the "Patient Information Form" and the "Diabetes Symptom Checklist Scale," and their HbA1c venous blood values were measured. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals in the three groups, and their HbA1c venous blood values were measured. In addition, telephone follow-up was conducted to determine whether the individuals had used the powdered extracts completely for 12 weeks. |
| Blueberry Group | Experimental | Other: Blueberry GroupBefore starting the study (pre-test/week 0), all group participants first completed the "Patient Information Form" and the "Diabetes Symptom Checklist Scale," and their HbA1c venous blood values were measured. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals in the three groups, and their HbA1c venous blood values were measured. In addition, telephone follow-up was conducted to determine whether the individuals had used the powdered extracts completely for 12 weeks. |
| Cranberry Group | Experimental | Other: Cranberry GroupBefore starting the study (pre-test/week 0), all group participants first completed the "Patient Information Form" and the "Diabetes Symptom Checklist Scale," and their HbA1c venous blood values were measured. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals in the three groups, and their HbA1c venous blood values were measured. In addition, telephone follow-up was conducted to determine whether the individuals had used the powdered extracts completely for 12 weeks. |
| Control Group | No intervention | –Before starting the study (pre-test/week 0), all group participants first completed the "Patient Information Form" and the "Diabetes Symptom Checklist Scale," and their HbA1c venous blood values were measured. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals in the three groups, and their HbA1c venous blood values were measured. |
Who may qualify
- Ages
- 18 years and older
- Sex
- All
- Healthy volunteers
- Not accepted
- Age groups
- Adult, Older adult
Key inclusion criteria (9 listed)
- Being 18 years of age or older,
- Volunteering to participate in the study,
- Being conscious and able to communicate,
- Having been diagnosed with T2DM at least 3 months prior and currently using oral antidiabetic medication,
- Be using one of the following powder extracts-bitter melon, blueberry, or cranberry-for the first time as a complementary treatment upon a physician's recommendation and be on the first day of use,
Key exclusion criteria (2 listed)
- Not meeting the inclusion criteria, having a known psychological disorder,
- Having previously received complementary therapy for DM, or having hearing loss.
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| Bitter Melon GroupPatients who voluntarily used bitter melon powder extract continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks. | Other | Bitter melon Group |
| Blueberry GroupPatients who voluntarily used bitter blueberry powder extract continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks. | Other | Blueberry Group |
| Cranberry GroupPatients who voluntarily used cranberry powder extract continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks. | Other | Cranberry Group |
Primary outcome
HbA1c
Time frame: 12 week
Unlike instant blood glucose values, HbA1c reliably reflects an individual's average blood sugar level over the past two to three months by measuring the amount of glucose bound to hemoglobin during the average lifespan of erythrocytes (approximately 120 days). Before starting the study (pre-test/week 0) HbA1c venous blood values were measured. Patients who voluntarily used bitter melon, blueberry, or cranberry continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks. At the end of the study (post-test/12th week), the was administered again to individuals HbA1c venous blood values were measured.
Diabetes Symptom Checklist Scale
Time frame: 12 week
The scale consists of a total of 34 items. These categories are: neurology (3, 11, 15, 21, 25, 34), psychology (1, 2, 4, 6, 17, 20), cardiology (5, 8, 9, 13, 24, 26, 29, 30), ophthalmology (10, 14, 22, 28), psychology/cognition (7, 19, 27, 31, 33), and hyperglycemia (12, 16, 23, 32) Subdimensionss. Responses on the scale are numbered from 0 to 5, with "0" meaning "none" and "5" meaning "extremely." Before starting the study (pre-test/week 0), all group participants first completed "Diabetes Symptom Checklist Scale" were measured. Patients who voluntarily used bitter melon, blueberry, or cranberry continued to consume 1 teaspoon (10 g total) of powdered extract mixed with yogurt or water twice a day (morning and evening) for 12 weeks. At the end of the study (post-test/12th week), the "Diabetes Symptom Checklist Scale" was administered again to individuals were measured.
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 21 Nov 2025.
- Individual participant dataSharing planned: No. Maybe I will decide later.
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Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Hatice Demirağ principal investigator
Study Principal Investigator Gümüşhane Universıty
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Bitter Melon Group, Blueberry Group and Cranberry Group in people with Type 2 Diabetes Mellitus and Symptoms and Signs, run by Hatice Demirağ, Ph.D at 1 site in Turkey (Türkiye).
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 9 inclusion and 2 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 21 Nov 2025. 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 Turkey (Türkiye). 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. 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?
HbA1c (time frame: 12 week). The study lists 2 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 21 Nov 2025; AzTrials last refreshed its copy on 6 Nov 2026.