据我国卫生部信息中心的报道,城市地区前十位的肿瘤为肺、胃、肝、食管、结直肠肛门、白血病、乳腺、鼻咽、膀胱和子宫癌。肿瘤的病因至今尚未清楚,但国内外学者认为80%-90%的病因与环境因素有关。根据估计,吸烟因素占30%,饮食因素占35%,生育和性行为因素7%,职业因素4%,酒精因素3%,地理因素3%,污染因素20%,药物和医疗因素1%。近年来,不少学者认为肿瘤的发生是多因素综合作用的结果,其中以饮食污染因素比重较大。某些营养素的缺 According to the report of the Ministry of Health Information Center of China, the top ten tumors in urban areas are lung, stomach, liver, esophagus, colorectal anus, leukemia, breast, nasopharyngeal, bladder and uterine cancer. The cause of the tumor has not yet been clearly known, but scholars at home and abroad believe that 80% to 90% of the causes are related to environmental factors. According to estimates, smoking accounted for 30%, dietary factors accounted for 35%, fertility and sexual behavior factors 7%, occupational factors 4%, alcoholic factors 3%, geographical factors 3%, pollution factors 20%, drugs and medical factors 1%. In recent years, many scholars believe that the occurrence of cancer is the result of the combined effects of multiple factors, of which the proportion of dietary contamination is relatively large. The lack of certain nutrients