Some determinants of whole-gut transit time: a population-based study.

Slow whole-gut transit time may be associated with an increased risk of gallstones, and possibly bowel cancer, but its determinants are unknown. We looked for these determinants in a community-based study of 884 women aged 25-69 years and 677 men aged 40-69 years. Transit time was estimated using prospective examination of three stools and a questionnaire about bowel habit. Diet and alcohol intake were assessed using a validated food frequency questionnaire. In women < 50 years not taking oral contraceptives, mean transit time was relatively constant across 10-year age bands (62 to 63 h). In older women it was also relatively constant, but was significantly shorter (58 to 59 h), suggesting an effect of female sex hormones. In women taking oral contraceptives, mean transit-time was 6 h longer than in women of the same age not taking them (95% CI 1.4 to 10.6 h). In men drinking > 40 g alcohol/day, mean transit time was 49 h compared with 54 h in those drinking < 20 g/day (p < 0.0001). In alcohol-abstaining men, an effect of dietary NSP (non-starch polysaccharide or fibre) intake was clearly apparent. Alcohol consumption quickened transit in both sexes; oral contraceptive usage slowed it in women. Body mass index in both sexes, soluble NSP in men, and insoluble NSP in women also significantly and negatively affected transit time. The food groups which were related to transit time were potatoes and cooked fruit in men, and pulses and bread in women.(ABSTRACT TRUNCATED AT 250 WORDS)