The effect of Chinese tea on the occurrence of esophageal tumors induced by N-nitrosomethylbenzylamine formed in vivo.

Five groups of rats (22 per group) were intubated with precursors of N-nitrosomethylbenzylamine (NMBzA), i.e., methylbenzylamine (1 mmol/kg body wt) and sodium nitrite (0.5 mmol/kg body wt), and with five different varieties of Chinese tea twice a week. One positive control group was intubated with precursors of NMBzA without tea, and a negative control group was given tap water and sodium nitrite only. After 12 weeks of treatment, significantly fewer lesions and papillomas in the esophageal mucosa were found in the tea-treated group than in the positive control group. The results confirmed the anticarcinogenic effects of Chinese tea in rats by blocking the in vivo formation of NMBzA.