Background and purpose: There have been few studies of the risk factors associated with colorectal cancer in Taiwan, a country of low incidence of the disease. This study investigated whether dietary and lifestyle factors correlate with colorectal cancer risks in Taiwan.
Methods: A total of 352 patients with colon cancer and 375 patients with rectal cancer histologically confirmed between 1995 to 1999 at a medical center in northern Taiwan were included in the study. They were age- and gender-matched with 736 healthy controls who were recruited from the health examination clinic at the same hospital. Dietary intake and lifestyle variables were ascertained using a standardized questionnaire. Unconditional multiple logistic regression was used to estimate odds ratios (ORs) and 95% confidence intervals (CIs).
Results: The risk of colon cancer and of rectal cancer was inversely associated with vegetable/fruit consumption in both men and women. The adjusted ORs based on the highest versus the lowest tertile consumption were 0.36 (95% CI, 0.21 to 0.61) and 0.44 (95% CI, 0.27 to 0.72) for men, respectively. The corresponding ORs for women were 0.32 (95% CI, 0.19 to 0.56) and 0.39 (95% CI, 0.23 to 0.69), respectively. However, the highest versus the lowest tertile meat consumption was associated with significantly elevated risk in both men and women for both colon cancer (ORs, 1.85 and 2.29, respectively) and rectal cancer (ORs, 2.32 and 2.42, respectively). Risk also increased with less exercise, low or moderate coffee consumption, cigarette smoking and alcohol intake, and decreased with the frequency of fish/shrimp consumption among men.
Conclusions: Consistent with the findings of previous studies in Western populations, this study found that vegetable and fruit consumption, less meat consumption, and exercise were associated with a reduced incidence of colorectal cancer in Taiwanese.