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

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.

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.

Exclusion criteria

• Not meeting the inclusion criteria, having a known psychological disorder,
• Having previously received complementary therapy for DM, or having hearing loss.