Supplementary Material for: Green Tea Polyphenols Ameliorate Esophagitis rather than Aspirin in a Non-randomized Prospective Cohort Study

Introduction: Green tea polyphenols (GTPs) and aspirin were demonstrated to be novel candidates for cancer chemoprevention. This study aimed to investigate effects of GTPs and aspirin on esophageal diseases.
Methods: This non-randomized prospective cohort study recruited participants from January 2012 to January 2013, who self-reported long-term GTPs intake, aspirin intake and no medicine use in questionnaire and underwent gastroscopy. Regression was defined as any reversal of process from normal epithelium to esophageal high-grade intraepithelial neoplasia. The primary outcome was regression rates after a one-year follow-up.
Results: A total of 159, 151,160 participants self-reported GTPs intake, aspirin intake, and no medication. After one year, 78, 81, and 83 participants received follow-up endoscopy in GTPs, aspirin, and control groups, respectively. There was no statistically significant difference in baseline pathology between the final cohort and lost to follow-up group. The average age of participants was 50.11  5.62 years old, consisting of 42 female and 200 male. The regression rates of esophageal precursor diseases were 68%, 55%, and 48% in GTPs, aspirin, and control groups, respectively (P = 0.036). Analyzing esophagitis subgroup, the regression rate of GTPs group (43/69, 62%) was significantly higher than aspirin group (32/67, 48%) and control group (27/70, 39%) (P = 0.019). One person experienced nausea for GTPs (1/159) and one person experienced gastrointestinal bleeding in the aspirin group (1/151).
Conclusions: GTPs, rather than aspirin, was associated with esophagitis remission compared with the control group. The benefits of GTPs on esophageal precursor diseases make it a promising health supplement.