Dietary fiber has been reported to have no association with colorectal adenoma and cancer. However, this topic remains controversial.
In this study, researchers from the United States used a food frequency questionnaire to assess the relationship between fiber intake and the frequency of colorectal adenoma.
The team undertook this study within the Prostate, Lung, Colorectal, and Ovarian (PLCO) Cancer Screening Trial. This was a randomized controlled trial designed to investigate methods for early detection of cancer.
The researchers assessed the fiber intake of 33,971 participants who were sigmoidoscopy-negative for polyps. They compared this with 3591 cases who had at least 1 histologically verified adenoma in the distal large bowel.
|Subjects in the highest quintile of dietary fiber intake had a 27% lower risk of adenoma.|
The team calculated odds ratios using logistic regression analysis.
The researchers found that high intake of dietary fiber was associated with a lower risk of colorectal adenoma, once other risk factors were taken into account.
They determined that study subjects in the highest quintile of dietary fiber intake had a 27% lower risk of adenoma than those in the lowest quintile.
They also found that the inverse association was strongest for fiber from grains and cereals, and from fruits.
Furthermore, the team calculated that risks were similar for advanced and non-advanced adenoma.
However, risk of rectal adenoma was not significantly associated with fiber intake.
Dr Ulrike Peters's team concluded, "Dietary fiber, particularly from grains, cereals, and fruits, was associated with decreased risk of distal colon adenoma".