Modification by fiber of toxic dietary effects.

There is evidence that type of diet may affect the course of chemical carcinogenesis. In experiments with acetylaminofluorene, rats maintained on stock diet exhibit fewer tumors than do rats fed semi-purified diets. Rats fed stock diet augmented with high levels of sodium cyclamate (2.5-10%), amaranth (5%) or Tween (15%) showed normal weight gain, whereas addition of these toxicants to a fiber-free basal diet caused severely restricted weight gain and decreased survival. The latter effect can be overcome by addition of 10% pectin, alfalfa or cellulose to the basal diet. On the other hand, mice fed a fiber-free diet survived pneumococcal infection better than did mice fed modified stock diets. The mechanism(s) by which fiber affects carcinogenicity or toxicity are unelucidated. The effect of fiber and other aspects of diet on drug action is an area of research that should be developed.