The Study
Dietary fiber and colorectal cancer risk: a nested case-control study using food diaries.
This study found that people who ate more fiber tended to have less colorectal cancer, but it didn’t make people change their diets to test it. So we can’t say fiber definitely causes the lower risk — maybe people who eat fiber also exercise more or smoke less.
Analysis score
Maximum 58 for a case-control study.
Where the score came from
Scientists looked at what people ate using detailed food diaries and found that those who ate more fiber relative to their total food energy had much lower chances of getting colon cancer.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 555 / 100
Quality score
Researchers compare people who have a condition (cases) with similar people who do not (controls), looking back in time for differences in exposure. Useful but more prone to bias.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — this suggests that choosing high-fiber foods like whole grains, beans, and vegetables instead of sugary or fatty foods may help protect against colon cancer.
- 2People who ate the most fiber relative to calories had 34% lower odds of colon cancer (OR=0.66).
- 3For every small increase in fiber per calorie, risk dropped 17%.
- 4Food surveys missed this link.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
Journal of the National Cancer Institute
Year
2010
Authors
C. Dahm, R. Keogh, E. Spencer, D. Greenwood, T. Key, I. Fentiman, M. Shipley, E. Brunner, J. Cade, V. Burley, G. Mishra, A. Stephen, D. Kuh, I. White, R. Luben, Marleen A. H. Lentjes, K. Khaw, Sheila A Rodwell Bingham
Related Content
Claims (6)
People who consume more dietary fiber relative to their total energy intake have a lower likelihood of developing colorectal cancer.
Adults who consume more dietary fiber, based on detailed food records, have a lower statistical likelihood of developing colorectal cancer compared to those with the lowest fiber intake, even after accounting for other lifestyle and dietary factors.
People who consume more dietary fiber relative to their total energy intake have a lower risk of developing colorectal cancer compared to those with the same amount of fiber but higher overall calorie intake.
The way people report how much fiber they eat affects whether studies find a link between fiber and colorectal cancer. When people use food diaries, a protective link is seen; when they use questionnaires, no significant link is found.
People who consume more dietary fiber have a lower risk of developing colon cancer compared to those who consume less, and this protective effect appears to be stronger for colon cancer than for rectal cancer.
When measurement errors in dietary records are corrected using statistical methods, the link between higher fiber intake and lower risk of colorectal cancer becomes stronger, suggesting that earlier studies may have missed part of this protective effect due to inaccurate reporting.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.