Food intake and colorectal adenomas: a case-control study in Malaysia

It is well established that almost all colorectal cancers arise from benign, neoplastic adenomatous polyps. In previous studies, intake of fruits, vegetables and legumes were found to decrease the risk for colorectal adenomas (CRA) and colorectal cancer. This case-control study aimed to evaluate the roles of a variety of foods in contributing to the risk of CRA in Malaysian subjects. One hundred and eighteen subjects were recruited into case (n=59) and control (n=59) groups at Hospital Kuala Lumpur (HKL). A pre-tested quantitative food frequency questionnaire (FFQ) was used to record the types of food items and frequency consumed. Logistic regression was used to determine the crude and adjusted odds ratios of the independent variables. Soy bean and soy products were associated with a reduced risk for CRA (OR = 0.38, 95% CI = 0.15-0.98), while tubers were associated with increase in risk four-fold (OR = 4.14, 95% CI = 1.60-10.70) and red meat intake was found to increase the risk two and a half-fold (OR = 2.51, 95% CI = 1.02-6.28). Higher servings of fruits and vegetables were found to significantly decrease the risk (OR fruits = 0.47, 95% CI = 0.30-0.74; OR vegetables = 0.49, 95% = 0.29-0.80). In conclusion, our data support protective roles for soy, fruits and vegetables in the aetiology of colorectal adenomas and increase in risk in those with high intakes of red meat and tubers. Food intake of an individual may have an influence on one's risk for developing CRA. This finding warrants further investigation before the protective effect of these food items is to be accepted. New studies should explore the possibility of these associations among individuals in the general population especially with regard to different ethnic or other groups in Malaysia with low fruit and vegetable consumption.