Association of fruit and vegetable consumption with colorectal adenoma among adults in Korea: a cross-sectional study

Colorectal adenomas (CRA) are critical target precursors in the carcinogenesis of colorectal cancer (CRC), and the association of dietary factors, including fruits and vegetables, with CRA is yet to be clearly understood, especially in Asian populations. It is necessary to study the association of fruit and vegetable consumption with CRA to guide interventions for the primary prevention of CRA in the general population. Therefore, this study examined the relationship of fruit and vegetable consumption with CRA among asymptomatic adults in Korea.

We identified 1,658 (61.2%, men) adults without a history of CRC who underwent colonoscopy as part of routine health screening at the Seoul National University Hospital Healthcare System Gangnam Centre from May to December 2011. Trained gastroenterologists diagnosed low- and high-risk CRA, and dietary information was assessed by trained nutritionists using a validated food frequency questionnaire (FFQ). Fruit and vegetable consumption was estimated in g/day per 1,000 kcal and stratified into quartiles. Multivariable-adjusted polytomous regression models were used to estimate the odds ratio (OR) and 95% confidence interval (CI) of CRA by quartiles of fruits and vegetable consumption at a two-sided P<0.05.

Overall, 536 (32.3%) presented with CRA. The multivariable-adjusted OR (95% CI) for odds of CRA by quartiles of total fruits and vegetable consumption were 1.00, 1.19 (0.85, 1.67), 1.23 (0.88, 1.72), and 1.02 (0.71, 1.46) (P for trend =0.87) for low-risk CRA and 1.00, 1.32 (0.81, 2.13), 0.76 (0.44, 1.31), and 0.58 (0.31, 1.06) (P for trend =0.02) for high-risk CRA. Similar but statistically insignificant trends were observed for vegetables or fruits individually.

Higher fruit and vegetable consumption is modestly associated with a lower odds of high-risk CRA, but longitudinal studies are necessary to validate these findings.