Impact of Green Tea Consumption on Postoperative Ileus in Colon Cancer Patients: A Pilot Randomized Controlled Trial

Introduction The consumption of caffeine-rich green tea has been shown to promote recovery of postoperative gastrointestinal function after subtotal gastrectomy. However, the beneficial effects of green tea on colon cancer have not been clarified. This pilot study aimed to evaluate the impact of green tea intake on postoperative outcomes after colon cancer surgery. Method This study describes the findings of a single-center stratified randomized controlled trial. Colon cancer patients who underwent laparoscopic or restorative colon resection were randomly assigned to a postoperative green-tea-drinking or water-drinking group. The primary outcome was time to first defecation (hours). Secondary outcomes were the length of hospital stay, postoperative ileus, postoperative complications, mean daily fluid intake (mL), and the incidence of all adverse events. The protocol was registered with UMIN (UMIN000048174). Results A total of 18 patients were enrolled and eight were assigned to the green-tea-drinking and 10 to the water-drinking group. Patient characteristics were similar in both groups. The time to first defecation was 42.0 ± 21.8 hours in the green-tea-drinking and 49.4 ± 42.2 hours in the water-drinking group (p=0.79). There were also no significant differences in postoperative hospital stay (p=0.28) or mean daily fluid intake (p=0.07). In the green-tea-drinking group, one patient developed postoperative ileus, and another experienced pseudogout, showing no significant difference compared with the water-drinking group (p=0.09). Conclusions In this pilot single-center stratified randomized controlled trial, drinking either green tea or water after laparoscopic or open colon cancer surgery was safe and made no difference to the primary or secondary outcomes.