Tea Polyphenol Intake and Changes in Serum Pepsinogen Levels

Abstract

Following a phase I study, a phase II study was conducted to evaluate the effects of two different doses of tea polyphenols on serum pepsinogen levels. Subjects were patients aged 40 to 69 years who had undergone gastroscopy between 1995 and 1997 at Aichi Cancer Center Hospital, and had been found to have no disease requiring medication. Those with pepsinogen I <70 ng/ml and pepsinogen I/II ratio ?6 were included in this study. Capsules containing 100 mg of tea polyphenols were administered for 1 year: 1 capsule per day for 101 patients (42 males and 59 females), and 6 capsules (equivalent to 10 cups) per day for 83 patients (30 males and 53 females). The enrollment of the 1 capsule group preceded that of the 6 capsule group, in which re‐participation was allowed. Blood samples were obtained 1 year after participation from 86 participants of the 1 capsule group and 77 participants (43 new participants and 34 re‐participants) of the 6 capsule group. The compliance in polyphenol capsule intake ranged from 11.4 to 105.7% (87.6% on average) of the scheduled amount for the 1 capsule group and 3.2 to 112.3% (77.8% on average) for the 6 capsule group. No serious polyphenol‐related adverse effects were reported. The difference in pepsinogen I between before and after 1 year intake of the polyphenol was 3.1 ng/ml for the 43 participants of the 6 capsule group, but 3.5 ng/ml for the 1 capsule group. The mean pepsinogen I/II ratio for the 43 participants increased from 2.37 by 0.08. This increase was not larger than that for the 1 capsule group (from 2.61 by 0.11). Among 34 participants in both interventions, no significant increase in pepsinogen I and I/II ratio for the 6 capsule intervention was observed. This result suggests that additional polyphenol intake for 1 year in Japanese does not improve pepsinogen levels, which are considered to reflect stomach atrophy, a high‐risk condition for stomach cancer.