The Study
Processed and Unprocessed Red Meat and Risk of Colorectal Cancer: Analysis by Tumor Location and Modification by Time
This study watched a big group of people for many years to see who got colon cancer and what they ate. It found that people who ate more processed meat (like bacon or hot dogs) were more likely to get cancer in the lower part of the colon. But because it didn’t randomly assign people to eat different things, we can’t say for sure that the meat caused the cancer — just that they’re linked.
Analysis score
Maximum 72 for a cohort study.
Where the score came from
Scientists looked at whether eating different kinds of red meat affects the chance of getting colon cancer, and where in the colon the cancer might form.
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 552 / 100
Quality score
Groups of people are followed over time to see who develops an outcome. Strong for identifying risk factors and associations, but cannot prove causation as firmly as RCTs.
Key takeaways
Summary
Based on the study abstract and findings.
- 1The type and timing of meat matter: processed meat over many years increases risk, while unprocessed meat doesn't seem to raise risk and may appear protective due to other healthy habits.
- 2Eating one serving of processed meat (like bacon or hot dogs) every day was linked to 36% higher chance of cancer in the lower part of the colon.
- 3Eating unprocessed red meat (like steak) was linked to 25% lower risk in that same area, but this might be because those people ate healthier overall.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
PLoS ONE
Year
2015
Authors
A. Bernstein, M. Song, Xuehong Zhang, A. Pan, Molin Wang, C. Fuchs, N. Le, A. Chan, W. Willett, S. Ogino, E. Giovannucci, Kana Wu
Related Content
Claims (6)
Regular red meat, like steak or roast, isn't the same as processed stuff like bacon or hot dogs — they're made differently and might affect your health in different ways, so experts say we shouldn't treat them the same when studying their health effects.
Eating more unprocessed red meat might seem linked to lower risk of a certain type of colon cancer in health pros, but it's probably because these folks eat healthier overall — not because the meat itself is protective.
Eating processed red meat in the last few years doesn’t seem to raise the risk of a certain type of colon cancer in US health pros — it might be how much you've eaten over a lifetime that matters more.
Eating more processed red meat — like bacon or hot dogs — is linked to a higher chance of getting a certain type of colon cancer, especially if you've been eating it for years. Cutting back could help lower your risk.
Eating unprocessed red meat every day might slightly increase the chance of getting a type of colon cancer, but the data isn’t strong enough to say for sure — it could just be chance.
Eating processed red meat every day doesn’t seem to raise the risk of a specific type of colon cancer in US health workers — the study found no real link, and it might even depend on where in the colon the cancer starts.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.