1 Department of Preventive Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
2 Department of Nutritional Science and Food Management, Ewha Womans University, Seoul 120-750, Republic of Korea
3 Center for Colorectal Cancer, National Cancer Center, Goyang-si, Republic of Korea
4 Molecular Epidemiology Branch, Research Institute, National Cancer Center, Goyang-si, Republic of Korea
Purpose
The colors of vegetable and fruit reflect their contents of unique phytochemicals and micronutrients which may contribute to health promotion. In this case-control study, we aimed to investigate the relationship between vegetable and fruit classified by color and colorectal cancer risk.
Methods
A case-control study was conducted with 923 colorectal cancer patients and 1846 controls recruited from the National Cancer Center in Korea. Information on dietary intake was collected using a food frequency questionnaire (FFQ) with 106 items. We classified vegetable and fruit into four groups by the color of their mainly edible part (eg, green, orange/yellow, red/purple and white). Vegetable and fruit intake level was classified by sex-specific tertile of control group. Residual method was used to adjust total energy intake. Binary and polytomous logistic regression models were used to estimate odds ratios and their 95% confidence intervals.
Results
High intake of total vegetable and fruit was strongly associated with a reduced risk of colorectal cancer in women (OR, 0.30; 95% CI 0.20-0.47 for highest vs. lowest tertile) and similar inverse association was observed for men (OR, 0.54; 95% CI 0.40-0.72). In color groups analysis, adjusted ORs (95% CI) comparing the highest vs. the lowest tertile of vegetable and fruit intake were: 0.47 (0.35-0.63) for green, and 0.50 (0.37-0.67) for white vegetable and fruit in men. An inverse association was also found in women for green (0.33 (0.21-0.51)), orange/yellow (0.65 (0.43-0.99)), red/purple (0.64 (0.43-0.96)) and white (0.29 (0.18-0.45)) vegetable and fruit.
Conclusion
We found a reduced risk of colorectal cancer among those with higher intake of vegetable and fruit of green or white as well as total intake amount in both men and women.
funding source
the National Research Foundation of Korea (2010–0010276 and 2013R1A1A2A10008260) and National Cancer Center Korea (0910220 and 1210141).