Randomised controlled trialcited by the Tayebat archiveabstract only checked A-SUP-17 standard review

Folic acid and bowel polyps

Folic acid for the prevention of colorectal adenomas: a randomized clinical trial.

Overview

Cole BF et al.. JAMA 2007 · PMID 17551129 · DOI 10.1001/jama.297.21.2351

No prevention of polyps; possible increase in advanced lesions (borderline).

Does the study support the specific claim? Partly · Methodological quality: moderate

Study explained simply

What did the researchers want to find out?: Adenoma prevention.
How was the study done?: RCT.
How many people, animals or samples were studied?: 1,021.
What was actually found?: No benefit.
How large was the observed effect?: RR 1.04; 1.67 advanced.
What do the results mean in everyday life?: Not useful for polyps.
What are the study's limitations?: Attrition.
What does it say about Elawady's specific claim?: Mixed.
Do the results apply to Germany and Europe?: Applicable.
What can explicitly not be concluded from this study?: Harm at fortification doses.

Authors: Cole BF, Baron JA, Sandler RS, Haile RW, Ahnen DJ, Bresalier RS, McKeown-Eyssen G, Summers RW, Rothstein RI, Burke CA, Snover DC, Church TR, Allen JI, Robertson DJ, Beck GJ, Bond JH, Byers T, Mandel JS, Mott LA, Pearson LH, Barry EL, Rees JR, Marcon N, Saibil F, Ueland PM, Greenberg ER, Polyp Prevention Study Group
Journal: JAMA
Year: 2007
Identifier: PMID 17551129 DOI 10.1001/jama.297.21.2351
Verification: verified – PubMed E-utilities efetch, 2026-10-25
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: not stated in abstract; grants: NCI NIH HHS

Does folic acid prevent colorectal adenomas?

Study design: Randomised controlled trial – Phase 3 double-blind placebo-controlled 2-factor RCT
Population: Recent colorectal adenoma history
Country: USA (9 centres)
Period: 1994–2004
Sample size: 1,021
Inclusion and exclusion criteria: see abstract

Results: First 3 years: adenoma RR 1.04 (0.90–1.20); advanced RR 1.32 (0.90–1.92). Second follow-up: adenoma RR 1.13 (0.93–1.37); advanced RR 1.67 (1.00–2.80, P=.05); more ≥3 adenomas and non-colorectal cancers.
Absolute risks: not reported in abstract
Authors' conclusion: Folic acid 1 mg/d does not reduce adenoma risk; possible increase in colorectal neoplasia needs research.

See results.

Vollset 2013 (I-SUP-07).

High: biology and trial populations comparable to European adults.

Borderline signal.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	low
Directness	direct
Reproducibility	not replicated
Consistency with the overall evidence	inconsistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	partly correct but over-interpreted

Note: according to the archive, the studies were compiled by the archive operators. Whether Dr. Elawady himself cited this study is not established.

What the archive says about the study: Listed in the archive bibliography of the oral-supplements rule without its own interpretation; used implicitly to support the rule summary that supplements 'failed or caused harm' in large trials.
A. What was actually studied?: Does folic acid prevent colorectal adenomas?
B. What did the authors find?: First 3 years: adenoma RR 1.04 (0.90–1.20); advanced RR 1.32 (0.90–1.92). Second follow-up: adenoma RR 1.13 (0.93–1.37); advanced RR 1.67 (1.00–2.80, P=.05); more ≥3 adenomas and non-colorectal cancers.
C. What conclusions do the authors themselves draw?: Folic acid 1 mg/d does not reduce adenoma risk; possible increase in colorectal neoplasia needs research.
D. What does the archive derive from it?: Bibliography support for folic acid harm.
E. Is this derivation scientifically justified?: Weak; not confirmed by Vollset 2013.
Adequacy of the interpretation (by the archive): partly correct but over-interpreted