High Fiber Intake May Lower Colon Tumor Risk

High fiber diet significantly decreased colorectal adenoma risk

/ Author:  / Reviewed by: Joseph V. Madia, MD Beth Bolt, RPh

(RxWiki News) Adding fiber to your diet is generally a healthy choice. It seems that fiber also may decrease the risk of getting a particular kind of colon tumor.

Colorectal adenomas are non-cancerous (benign) tumors of the colon that can transform into colon cancer. Finding effective strategies to prevent or decrease the risk of these tumors is the goal of much research.

A team of researchers recently analyzed what effect consumption of dietary fiber had on finding colorectal adenomas.

Their research showed that a high-fiber diet, including vegetable, fruit and grain sources of fiber, significantly decreased the risk of colorectal adenoma.

"Follow your doctor’s dietary advice for preventing colon cancer."

Qiwen Ben, from the Department of Gastroenterology in Ruijin Hospital at Shanghai Jiaotong University in Shanghai, China, was the lead researcher.

The research team analyzed 20 published studies performed in the US, Europe and Asia that included 10,948 people with colorectal adenoma. The studies all included assessments of dietary fiber intake by the study participants.

Different sources of fiber were identified and the researchers grouped the participants into high and low fiber intake groups. Fiber from vegetables, fruits and grains and total fiber intake were evaluated separately for association with colorectal adenoma.

Since there were 20 studies analyzed, the ranges of high versus low fiber intake varied. On average, high total fiber intake was 23.6 g/day, high vegetable fiber intake was 9.7 g/day, high fruit fiber intake was 7.5 g/day and the high grain fiber intake was 7.1 g/day.

On average, low total fiber intake was 12.8 g/day, low vegetable fiber intake was 2.9 g/day, low fruit fiber intake was 1.3 g/day and low grain fiber intake was 2.5 g/day.

Analysis of the association between dietary fiber and colorectal adenoma showed that increased fiber intake decreased the risk of colorectal adenoma.

Consuming a diet high in dietary fiber decreased the risk of colorectal adenoma by 28 percent compared to a diet low in dietary fiber. Every 10 g increase in fiber consumed per day resulted in a 9 percent decrease in risk.

Eating a diet high in cereal fiber decreased the risk of colorectal adenoma by 24 percent compared to low cereal fiber intake. Every 10 g/day increase in dietary fruit fiber decreased the risk by 30 percent.

High fruit fiber intake, but not high vegetable intake, was also associated with decreased risk of colorectal adenoma compared to low fiber intake.

According to the authors of this study, these findings, together with the fact that the average US and European dietary fiber intake is about 9 to 20 g/day less than the recommended intake, could help guide dietary choices for colorectal adenoma prevention.

This research was published in the March issue of Gastroenterology.

The National Natural Science Foundation of China provided funding for the study.

The authors disclosed no conflicts of interest.

Review Date: 
March 5, 2014
Last Updated:
March 6, 2014