Clinical and Salivary Antioxidant Effects of Matcha Tea in Patients with Gingivitis: A Randomized Controlled Trial

Introduction Gingivitis, the initial stage of periodontal disease, is characterised by inflammation driven by dental biofilm and associated with oxidative stress. Matcha tea, a powdered green tea rich in antioxidants, has shown potential health benefits. This study aimed to investigate the effect of Matcha tea consumption on clinical periodontal parameters and salivary antioxidant levels in patients with gingivitis. Methods A randomised controlled clinical trial was conducted with 41 participants diagnosed with gingivitis. Participants were randomly allocated to a Matcha tea group (n=21) who consumed two cups of Matcha tea daily for 30 days, or a control group (n=20) who received standard oral hygiene instructions. Primary outcomes were clinical periodontal parameters (Plaque Index [PI], Bleeding on Probing percentage [BOP%], Gingival Index [GI]), and secondary outcomes were salivary levels of Malondialdehyde (MDA), Superoxide Dismutase (SOD), and Glutathione Peroxidase 1 (GPX1), assessed at baseline and after 30 days. Results Both groups showed significant within-group improvements in PI, BOP%, and GI at the 30-day follow-up ( p <0.01). However, there were no statistically significant differences in these clinical parameters between the Matcha tea and control groups at the endpoint. The Matcha tea group exhibited a significant reduction in salivary MDA levels ( p =0.002) and significantly higher salivary SOD ( p =0.047) and GPX1 ( p =0.027) levels compared to the control group at the 30-day follow-up. Discussion The biochemical improvements are attributed to Matcha's potent antioxidants, which favorably modulate the oral redox balance. The lack of superior clinical outcomes suggests that the profound effect of mechanical plaque control may have overshadowed any adjunctive benefits from Matcha within the 30-day trial. This highlights a potential disconnect between systemic antioxidant modulation and localised clinical changes in gingivitis management. Conclusion Daily consumption of Matcha tea for one month favorably modulated salivary antioxidant biomarkers in patients with gingivitis, reducing lipid peroxidation and increasing antioxidant enzyme levels. However, these biochemical changes did not translate into statistically significant differences in clinical periodontal parameters beyond standard oral hygiene within this study's timeframe. Clinical Trial Registration Number NCT06912958