Effect of Using Bitter Melon, Blueberries and Cranberries on HbA1c and Diabetes Symptom Levels

NCT ID: NCT07233460

Last Updated: 2025-11-21

Basic Information

• Recruitment Status: COMPLETED
• Clinical Phase: NA
• Total Enrollment: 120 participants
• Study Classification: INTERVENTIONAL
• Study Start Date: 2024-02-06
• Study Completion Date: 2024-05-15

Brief 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.

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

Study Design

• Allocation Method: RANDOMIZED
• Intervention Model: PARALLEL
• Primary Study Purpose: SUPPORTIVE_CARE
• Blinding Strategy: DOUBLE

Study Groups

Bitter melon Group

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.

Group Type: EXPERIMENTAL

Bitter Melon Group

Intervention Type: OTHER

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 Group

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.

Group Type: EXPERIMENTAL

Blueberry Group

Intervention Type: OTHER

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 Group

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.

Group Type: EXPERIMENTAL

Cranberry Group

Intervention Type: OTHER

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.

Control Group

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.

Group Type: NO_INTERVENTION

No interventions assigned to this group

Interventions

Bitter Melon Group

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.

Intervention Type: OTHER

Blueberry Group

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.

Intervention Type: OTHER

Cranberry Group

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.

Intervention Type: OTHER

Eligibility Criteria

Inclusion Criteria

• 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,
• No allergy to bitter melon, blueberry, or cranberry,
• Not engaging in exercise,
• Taking 10g of bitter melon, blueberry, or cranberry powder extract daily.

• Having previously received complementary therapy for DM, or having hearing loss.

• Minimum Eligible Age: 18 Years
• Eligible Sex: ALL
• Accepts Healthy Volunteers: No

Sponsors

Karadeniz Technical University

OTHER

Sponsor Role: collaborator

Hatice Demirağ, Ph.D

OTHER

Sponsor Role: lead

Responsible Party

Hatice Demirağ, Ph.D

Assistant Professor

Responsibility Role: SPONSOR_INVESTIGATOR

Principal Investigators

Hatice Demirağ

Role: PRINCIPAL_INVESTIGATOR

Study Principal Investigator Gümüşhane Universıty

Locations

Gümüşhane University

Gümüşhane, , Turkey (Türkiye)

Countries

Turkey (Türkiye)

Other Identifiers

RCS05022024

Identifier Type: -

Identifier Source: org_study_id