A case-control study of roles of diet in colorectal carcinoma in a South Indian population.

INTRODUCTION:
The worldwide incidence of colorectal cancer has increased rapidly in the past few decades and dietary habits have been implicated in the cause. Though the Indian diet varies substantially from western diet, there have not been detailed studies on any association.

MATERIALS AND METHODS:
This is hospital based case control study enrolling 108 cases and 324 controls, all hailing from the Malabar region of Kerala, India. The subjects were interviewed using food frequency questionnaires for commonly consumed dietary items in the region.

RESULTS:
A strong association was found between colorectal cancer and tapioca (OR= 2.7 p= 0.001), beef (OR= 4.25, p= 0.000) and pungent spices (OR= 9.62, p= 0.018). Fruits and vegetables a showed strong inverse association (OR= 0.15 p= 0.002). Fish consumption on a daily basis showed a 25% reduction in risk on univariate analysis. Heavy consumption of sugar (OR= 2.80) and tobacco use (OR= 8.79) showed significant high risk.

CONCLUSIONS:
There is strong evidence from our study that intake of beef, refined carbohydrates and tobacco can promote colorectal cancer. Our study has also thrown light on some of the other commonly consumed items, like tapioca and spices, which have positive associations. These are commonly consumed in Malabar region of Kerala. A cohort study is now needed to confirm our findings.