Nigro N D, Bull A W
Prev Med. 1987 Jul;16(4):554-8. doi: 10.1016/0091-7435(87)90071-5.
The effect of dietary fiber on intestinal carcinogenesis in animals is controversial. Some find that the addition of wheat bran or cellulose inhibits intestinal cancer in rats, while others report no effect. Such mixed results often are due to differences in the design of experiments. One important aspect in this regard is the amount of fat in the diet. Some fiber supplements inhibit cancer formation when the fat content is normal but not when it is high. However, a recent epidemiological study in Scandinavia showed a lower cancer incidence in a rural population compared with an urban area, in spite of the fact that the dietary fat content was high in both regions. There was a modest difference in the amount of fiber, and this may not have accounted completely for the variation in cancer incidence. Other dietary factors might have added inhibitory response to help overcome the promotional effect of an excessive amount of fat. The interaction among dietary components must be considered when designing animal experiments to assess the effect of fiber on cancer development.
膳食纤维对动物肠道癌变的影响存在争议。一些人发现添加麦麸或纤维素可抑制大鼠的肠道癌，而另一些人则报告无此效果。这种混合的结果往往是由于实验设计的差异。这方面的一个重要因素是饮食中的脂肪量。当脂肪含量正常时，一些纤维补充剂可抑制癌症形成，但脂肪含量高时则不然。然而，最近在斯堪的纳维亚进行的一项流行病学研究表明，尽管两个地区的饮食脂肪含量都很高，但农村人口的癌症发病率低于城市地区。纤维摄入量存在适度差异，这可能并未完全解释癌症发病率的变化。其他饮食因素可能增加了抑制反应，以帮助克服过量脂肪的促进作用。在设计动物实验以评估纤维对癌症发展的影响时，必须考虑饮食成分之间的相互作用。
