Fruit and vegetable consumption and risk of colorectal cancer in Japan: The Miyagi Cohort Study.
OBJECTIVE
Adequate fruit and vegetable intake has been suggested to protect against colorectal cancer. However, several recent prospective studies have reported no association. We therefore examined the association between fruit and vegetable intakes and the risk of colorectal cancer in a prospective cohort study in Japan.


METHODS
Between June and August 1990, 47 605 Japanese men and women completed a self-administered questionnaire, including a food-frequency questionnaire. We divided the subjects into quartiles based on their self-reported fruit and vegetable consumption. There were 165 colon cancer and 110 rectal cancer incidences identified during 7 years of follow-up, to the end of December 1997. We used Cox proportional hazards models to estimate the relative risk (RR) of developing colorectal cancer according to the level of fruit and vegetable consumption, applying adjustments for potential confounders.


RESULTS
No statistically significant association was observed between fruit and vegetable consumption and the risk of colorectal cancer. The multivariate RR of colon cancer in the highest quartile of fruit and vegetable intake compared with the lowest was 1.13 (95% confidence interval (CI) 0.73-1.75), the RR for vegetables alone was 1.24 (95% CI 0.79-1.95) and that for fruit alone was 1.45 (95% CI 0.85-2.47). The corresponding multivariate RRs for rectal cancer were 1.12 (95% CI 0.67-1.89), 1.14 (95% CI 0.67-1.93) and 1.41 (95% CI 0.73-2.73).


CONCLUSIONS
We found no association between the consumption of fruit and vegetables and the risk of colorectal cancer among the Japanese population.
Sato
Yuki
Y
Division of Epidemiology, Department of Public Health and Forensic Medicine, Tohoku University Graduate School of Medicine, 2-1 Seiryo, Aoba, Sendai 980-8575, Japan. syukiki@mail.tains.tohoku.ac.jp
Tsubono
Yoshitaka
Y
Nakaya
Naoki
N
Ogawa
Keiko
K
Kurashima
Kayoko
K
Kuriyama
Shinichi
S
Hozawa
Atsushi
A
Nishino
Yoshikazu
Y
Shibuya
Daisuke
D
Tsuji
Ichiro
I
D000328:Adult; D015179:Colorectal Neoplasms / Q000517:prevention & control*; D004812:Epidemiologic Methods; D005247:Feeding Behavior; D005260:Female; D005638:Fruit; D006801:Humans; D007564:Japan; D008297:Male; D008875:Middle Aged; D014675:Vegetables