Benefits of Quercetin on Glycated Hemoglobin, Blood Pressure, PiKo-6 Readings, Night-Time Sleep, Anxiety, and Quality of Life in Patients with Type 2 Diabetes Mellitus: A Randomized Controlled Trial
What this study found
Quercetin was associated with broadly favorable effects and good tolerability. Compared with control, the intervention improved HbA1c (-4.0% vs 0.1%, p = 0.011), PiKo-6/FEV1 (5.6% vs -1.5%, p = 0.002), systolic blood pressure (-5.0% vs -0.2%, p = 0.029), night-time sleep (11.6% vs -7.3%, p < 0.001), anxiety (SAST-10: -26.2% vs 3.3%, p < 0.001), and SF-36 physical and mental quality-of-life scores (p < 0.001 for both). No meaningful changes were seen in diastolic blood pressure, BMI, waist circumference, total cholesterol, triglycerides, or LDL, and no major adverse events were reported.
- Study & population
- This was a randomized controlled trial in adults with type 2 diabetes mellitus managed with non-insulin therapies.
- Intervention
- The active intervention was oral quercetin dihydrate 500 mg once daily, added to standard diabetes care, versus control.
- Key limitation
- The trial was open-label and conducted at a single primary care site, which limits internal validity and generalizability.
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Open PDFOriginal abstract
Background: Diabetes is a rapidly growing global morbidity issue with high prevalence, and the associated dysglycemia leads to complications. Patients with type 2 diabetes mellitus (T2DM) often experience elevated anxiety levels, affecting their quality of life and diabetes management. This study investigated quercetin, a nutraceutical and potential senolytic with antioxidant activity, to detect its possible positive effect on the bio-clinical measurements and routine health of patients with T2DM. Methods: This prospective randomized controlled trial (RCT) investigated the clinical usefulness of quercetin in patients with T2DM receiving non-insulin medications. One hundred participants were stratified by age and sex (1:1) and randomized to control (n = 50) or intervention (n = 50) groups. The control received standard care only, while the intervention received 500 mg quercetin daily for 12 weeks, followed by an 8-week washout and a final consecutive 12-week supplementation period (total: 32 weeks), as adjunct to their usual care. Comprehensive health assessments, including blood analyses, were conducted at baseline and study termination. Quality of life and anxiety were assessed using the 36-item Short Form Health Survey (SF-36) and Short Anxiety Screening Test (SAST-10). Results: Eighty-eight patients with T2DM concluded the trial. Compared with the control, glycated hemoglobin (HbA1c) levels showed a significant decrease (Δ%-change: −4.0% vs. 0.1%, p = 0.011). Quercetin also significantly improved PiKo-6 readings (FEV1: 5.6% vs. −1.5%, p = 0.002), systolic blood pressure (−5.0% vs. −0.2%, p = 0.029), night-time sleep (11.6% vs. −7.3%, p < 0.001), anxiety levels (SAST-10) (−26.2% vs. 3.3%, p < 0.001), and quality of life (SF-36) (both physical and mental components, p < 0.001). Conclusions: Based on the current open-label study, quercetin appears to be a promising supplement for T2DM, providing lifestyle and care support. Further research is warranted to shift this potential from clinical usefulness and feasibility to multidisciplinary evidence.