Freeman H J, Spiller G A, Kim Y S
Cancer Res. 1978 Sep;38(9):2912-7.
The incidence, distribution, size, and histopathology of grossly visible colonic tumors induced by parenteral administration of 1,2-dimethylhydrazine were examined in rats fed either a chemically defined fiber-free diet or a nutritionally and calorically equivalent diet containing a purified fiber component, microcrystalline cellulose. This double-blind study indicates that cellulose ingestion was associated with reduced numbers of animals involved with colonic neoplasia as well as a reduction in the total numbers of colonic tumors. Furthermore, this protective effect of cellulose appears to be time dependent and associated with a shift in tumor distribution from the proximal colon to a more distal site. Cellulose fiber had no apparent effect on colonic tumor size, histopathology, or the incidence of other tumors known to occur in this experimental animal model. This study strongly supports the hypothesis that fiber is an important protective agent against colonic neoplasia development. While the mechanism for this protective effect remains obscure, it appears to be temporally related to the duration of fiber ingestion as well as to a differential fiber effect on either the luminal content or the mucosa of the proximal and distal colon.
给大鼠经肠胃外途径注射1,2 - 二甲基肼，诱导产生肉眼可见的结肠肿瘤，然后分别用化学成分明确的无纤维饮食或含有纯化纤维成分微晶纤维素的营养和热量相当的饮食喂养这些大鼠，检测结肠肿瘤的发生率、分布、大小及组织病理学。这项双盲研究表明，摄入纤维素与涉及结肠肿瘤形成的动物数量减少以及结肠肿瘤总数减少有关。此外，纤维素的这种保护作用似乎与时间有关，且与肿瘤分布从近端结肠向更远端部位的转移有关。纤维素纤维对结肠肿瘤大小、组织病理学或已知在该实验动物模型中发生的其他肿瘤的发生率没有明显影响。这项研究有力地支持了纤维是预防结肠肿瘤发生的重要保护剂这一假说。虽然这种保护作用的机制尚不清楚，但它似乎在时间上与纤维摄入的持续时间有关，也与纤维对近端和远端结肠的管腔内容物或黏膜的不同作用有关。
