Differential long-term dietary behavior effects of colon cancer prevention programs

Abstract

Increasing recognition of the importance of diet in the etiology of colon cancer has highlighted the need for methods to determine dietary intake of high risk nutrients. Colon cancer prevention programs (CCPPs) promote consumption of low fat, high fiber diets rich in fruits and vegetables. The purpose of this study was to examine one-year follow-up dietary habits and to determine differences between perceived and actual levels of fat intake in older adults who had participated in CCPPs involving either beta carotene or calcium-wheat bran fiber supplementation. Frequency of foods actually eaten and perceived level (high, medium or low) of fat intake were assessed using the Centers for Disease Control Behavior Risk Factor Survey (BRFS). A telephone survey was administered to 103 previous CCPP participants (average age 64). Differences in estimated grams of fat eaten were compared to perceived level of fat intake using one-way ANOVA. The BRFS-derived weekly fat intake estimates ranged from 38 to 447 grams. Compared to subjects reporting high or medium fat intake, those reporting low fat intake had significantly (p<.05) lower total weekly fat consumption. Furthermore, subjects who perceived their fat intakes as low also actually reported consuming significantly (p<.05) more fruits and vegetables and fewer servings of high fat meats. Expected differences by study were not found with subjects from the beta carotene trial not consuming significantly (p<.05) more servings of carrots as compared with the calcium-wheat bran fiber group. Likewise, calcium-wheat bran fiber participants did not consume higher amounts of calcium-rich foods. Although all subjects tended to consume low fat diets, many did not continue to eat foods rich in beta carotene or calcium and wheat bran fiber. These results suggest general, not specific, dietary behavior carry-over effects one year after participation in a CCPP