Whole Grains can Reduce the Risk of Developing Colorectal Cancer

A high fiber diet, especially rich in cereals and whole grain, can reduce the risk of colorectal cancer - thus concluded a research study published in the British Medical Journal.
Colorectal cancer, cancer that affects the large intestine, is among the most common cancers to affect people worldwide. The environment plays a role in determining the risk for colorectal cancer. This is evident from the fact that if people from areas with lesser incidence of colorectal cancer move into areas where it is more common and adopt their diet and lifestyle, the incidence of colorectal cancer in this migrant population becomes similar to that of the new place.
Diet, especially red and processed meat, and alcohol, have been shown to be associated with colorectal cancer. On the other hand, dietary fiber lowers the risk of colorectal cancer. Dietary fiber could protect against colorectal cancer by increasing bulk of stools and diluting any cancer causing substances in the digestive tract. It also enhances clearance, thus reducing the contact time of any cancer causing substances with the digestive tract. Dietary fiber gets converted into short chain fatty acids, which protect against colorectal cancer. However, which fibers are likely to provide benefit is not clearly known.

Whole grains are not only a good source of dietary fiber, but also contain antioxidants, vitamins, minerals, phytate, phenolic acids, lignans and phytoestrogens which may contribute to their anticancer effect. They also contain large amounts of folate and magnesium, which have known anticancer effects. Their ability to reduce weight and improve insulin resistance may also play a role in reducing cancer risk.
A group of reviewers analyzed 21 previously published studies with more than 14,500 cases to establish the role of dietary fiber and whole grains in preventing the development of cancer. They found that there was a 10% reduction in risk of developing colorectal cancer for each 10 g/day intake of total dietary fiber and cereal fiber and about a 20% reduction for each three servings (90 g/day) of whole grain daily. Further reductions in risk were observed with higher intake.
The study thus found that dietary fiber, cereal fiber and whole grains do reduce the risk for developing colorectal cancer.
However, fibers from other sources like fruits, vegetables and legumes do not appear to show the same beneficial effect.
Thus, a diet consisting of high fiber and whole grains does appear to reduce the risk of colorectal cancer. Besides, these foods also provide other health benefits. They contribute in preventing heart disease, diabetes, obesity and improve chances of survival. Thus, food rich in fiber and whole grains should definitely be a part of your daily diet.
Reference:
1. Dietary fibre, whole grains, and risk of colorectal cancer: systematic review and dose-response meta-analysis of prospective studies; BMJ 2011; 343 doi: 10.1136/bmj.d6617 (Published 10 November 2011).