Effect of green coconut water kombucha on hematological parameters among adolescents with mild anemia

Background: Anemia remains a major public health problem in Indonesia, particularly among adolescent girls. Mild anemia is often overlooked despite its negative effects on learning ability, concentration, productivity, and quality of life. Objective: This study aimed to analyze the effect of green coconut water kombucha on the hematological profile of adolescents with mild anemia. Methods: This pilot study used a quasi-experimental one-group pretest–posttest design without a control group. Of 30 adolescents screened, 12 aged 17–21 years with hemoglobin levels of 10.0–11.9 g/dL met the inclusion criteria, and all were enrolled (total sampling of eligible participants). Participants consumed 150 mL of green coconut water kombucha daily for 14 days. White blood cell (WBC), red blood cell (RBC), hemoglobin (Hb), hematocrit (HCT), and platelet (PLT) counts were measured before and after the intervention. Normality of the paired differences was assessed using the Shapiro–Wilk test, and the paired t-test or Wilcoxon signed-rank test was applied accordingly. Results: All parameters increased after the intervention. Mean Hb increased from 10.52 ± 0.36 to 12.03 ± 1.13 g/dL and HCT from 31.55 ± 1.08% to 36.10 ± 3.40% (both p < 0.001; paired t-test), and WBC from 6.63 ± 1.50 to 7.46 ± 1.41 ×10³/µL (p = 0.007). RBC showed a small increase (median 4.65 to 4.79 ×10⁶/µL; p = 0.037; Wilcoxon) that was sensitive to one participant with a large individual change. PLT increased (median 307.5 to 324.0 ×10³/µL; p = 0.002) with wide inter-individual variation. Conclusion: Within the limits of an uncontrolled pilot design, green coconut water kombucha showed potential to support improvement in hematological parameters, particularly Hb and HCT, in adolescents with mild anemia. These findings are preliminary and do not establish a causal effect; randomized controlled trials with larger samples, longer intervention periods, and control of dietary iron intake are needed.