Colorectal polyps and diet: A case‐control study in Marseilles

Abstract

This study investigates the differences in usual past diet between 252 subjects with newly diagnosed adenomatous or villous polyps of the colon and rectum and a group of 238 hospital controls. Cases and controls were interviewed in hospital by 3 nutritionists using a dietary history questionnaire focused on the diet during the preceding year. Nutrient intake was estimated by means of ad hoc food tables adapted from French and British tables. Out of 16 food groups considered in the analyses, the cases reported lower consumption of oil and potatoes and higher consumption of sugar added to food and drink. Among nutrients, we found that cases had a lower consumption of carbohydrates (not taking into account added sugar), potassium, magnesium and vitamin B6. We found a slightly lower intake of fibre and a slightly higher intake of saturated fat among cases, though neither was statistically significant. Intake values for fibre and for carbohydrates were highly intercorrelated and, due to measurement errors, the effect of one may be masked by the other and vice versa. The hypothesis that some components of carbohydrates (starches, fibre and natural sugars but not added sugar) play a protective role in relation to the biology of tumours of the intestinal tract is considered in further multivariate analyses and in the "Discussion".

Colorectal adenomas and diet: a case-control study of subjects participating in the Nottingham faecal occult blood screening programme

“…With regard to protein intake our finding of no association is consistent with all but one (Macquart-Moulin et al, 1987) of the previous studies. Lack of, or inverse association with fat and protein is consistent with a large Japanese study in which frequency of consumption of certain food groups were compared between cases with symptomatic adenomas and population-based controls (Kato et al, 1990).…”

“…The association with total fat found in the study of Giovannucci et al is largely accounted for by saturated fat. Positive associations with this nutrient have also been found in two other studies (Macquart-Moulin et al, 1987;Neugut et al, 1990) although in both studies some or all cases were symptomatic.…”

“…The median intake of fibre was somewhat higher than that reported in the studies of Macquart-Moulin et al (1987) and Giovannucci et al (1992), in both of which an inverse association with high fibre intake was found, but the variability of intake was similar between the studies. Willett (1989a) observed that in all eight case-control studies of colorectal cancer in which the source of fibre were examined separately, grain fibre or cereal intake was either unrelated or positively associated with the disease, whilst intake of fibre from fruits and vegetables was protective, an effect also observed in two additional case-control studies.…”

“…The proportion of cases with small adenomas is likely to have been substantially lower in the present study that in other studies. For example, the proportion of cases whose largest adenoma was less than 1 cm in maximum diameter was 30% in the present study, in contrast to 66% in the study of Macquart-Moulin et al (1987). Therefore, our study should have had greater power to detect associations with large adenomas, which are the most likely to be associated with malignant changes (O'Brien et al, 1990;Gatteschi et al, 1991;Chantereau et al, 1992).…”

“…No such association has been found in the other studies in which (Macquart-Moulin et al, 1987;Giovannucci et al, 1992) and it is quite possible that this is a chance finding.…”