Consuming a diet rich in fibre does not lower the risk of cancer of the colon or rectum. Researchers from the National Institutes of Health, Bethesda, Maryland conducted a study and found that there was no association between how much dietary fibre one eats and the risk of colorectal cancer. However, consumption of whole grain foods lowers the risk of developing this cancer. The researchers analysed survey responses from more than 291,000 men and 197,000 women between 50 and 71 years old. The range of daily dietary fibre for the whole group was 6.6 grams per kilocalories for the lowest amount to 15.9 grams per kilocalories for the highest amount. The corresponding range for men was 6.4 to 15.2, and for women, 7.0 to 16.8. After analysing fibre from different food sources it was found that only fibre from grains was associated with a lower risk of colorectal cancer. The risk of colorectal cancer was lowered by 14 percent among the subjects with the highest amounts of grain in their diet compared with those with the lowest amounts. The protective effect of whole grains was stronger for rectal than for colon cancer. Nevertheless, the findings support the recommendation of eating more unprocessed cereals or pulses and avoiding refined starchy foods to lower the risk of colorectal cancer.
American Journal of Clinical Nutrition,
May 2007