Diet, nutrition intake, and metabolism in populations at high and low risk for colon cancer. Composition, intake, and excretion of fiber constituents.

The role of fiber in human diet in preventing a number of chronic diseases has been a widely debated topic in recent years. The claim that populations at low risk for colon cancer generally consume a more fiber-rich diet than those at high risk, has been used to postulate a protective role for this group of substances. In this study we asked the question whether populations leading different dietary lifestyles and who are at varying risks for colon cancer show marked differences in their dietary and fecal profiles of various fiber components. Four study groups consisting of Seventh-day Adventist (SDA) pure vegetarians, SDA lacto-ovo vegetarians, SDA nonvegetarians, and a group of general population nonvegetarians were selected from the greater Los Angeles Basin area. Three-day composite diets, and stools were analyzed for neutral detergent fiber (NDF), hemi-cellulose, lignin, cellulose, cutin + silica, and pectin. The percentage composition and the daily intake and output of each of these components were computed for each population group. The dietary profile revealed a trend (not statistically significant) toward generally higher daily intake values among the vegetarian subgroups, neutral detergent fiber values in g/day: SDA pure vegetarians, 63.0 +/- 7.9; SDA-lacto-ovo vegetarians, 55.8 +/- 3.5; SDA nonvegetarians, 57.2 +/- 3.5; general population nonvegetarians, 52.5 +/- 4.9), lignin, cellulose, and pectin being the major contributors to this difference.(ABSTRACT TRUNCATED AT 250 WORDS)