Dietary patterns and colorectal cancer risk in middle-aged adults: A large population-based prospective cohort study.

BACKGROUND & AIMS: A finding between dietary pattern and cancer may provide visions beyond the assessment of individual foods or nutrients. We examined the influence of dietary pattern with colorectal cancer (CRC) among a Japanese population.

METHODS: A total of 93,062 subjects (43,591 men, 49,471 women) who participated in the Japan Public Health Center-based Prospective Study were followed from 1995-1998 to the end of 2012, during which 2482 cases of CRC (1514 men, 968 women) were newly identified. Dietary data was obtained from a validated food-frequency questionnaire between 1995 and 1998.

RESULTS: Three dietary pattern was derived from principal components factor: prudent, westernized, and traditional pattern. After controlled for potential confounders, the prudent pattern showed a decreased association of CRC risk in men (HR for highest quintile vs lowest: 0.85; 95% CI: 0.72-1.00; P trend <0.05), slightly more strongly with distal colon cancer (P trend <0.05); but an increased risk of rectal cancer in women (P trend <0.05). The westernized pattern showed a significant positive linear trend for colon (P trend <0.05) and distal cancer (P trend <0.05) in women. There was no apparent association of traditional Japanese dietary pattern on the overall or any specific sites risk of CRC.

CONCLUSIONS: A prudent dietary pattern showed an inverse association with CRC risk in men, and a westernized pattern was related with a higher risk of colon and distal cancer in women.