Cohort studyindependent cross-checkabstract checked I-VEG-125 standard review

Vegetable nitrate not linked to bowel cancer

Source-specific nitrate and nitrite intake and association with colorectal cancer in the Danish Diet, Cancer and Health Cohort.

Overview

Erichsen DW et al.. Environ Int 2025 · PMID 40628182 · DOI 10.1016/j.envint.2025.109658

In 54,610 Danes, nitrate from vegetables was not linked to colorectal cancer; high nitrate in tap water was linked to distal colon cancer.

Does the study support the specific claim? No · Methodological quality: moderate

Study explained simply

What did the researchers want to find out?: Relate nitrate sources to bowel cancer.
How was the study done?: Cohort.
How many people, animals or samples were studied?: 54,610 adults.
What was actually found?: Food nitrate null; tap water positive.
How large was the observed effect?: HR 1.48 tap water.
What do the results mean in everyday life?: Vegetable nitrate is not a bowel-cancer risk in this cohort.
What are the study's limitations?: Observational; subgroups.
What does it say about Elawady's specific claim?: Contradicts the claim.
Do the results apply to Germany and Europe?: European.
What can explicitly not be concluded from this study?: Cannot exclude small effects.

Authors: Erichsen DW et al.
Journal: Environ Int
Year: 2025
Identifier: PMID 40628182 DOI 10.1016/j.envint.2025.109658
Verification: verified – PubMed efetch 2026-10-26; Crossref 2026-10-26
Retracted: no
Corrections: none
Extent checked: abstract only
Conflicts of interest and funding: COI statement: Declaration of competing interest The authors declare the following financial interests/personal relationships which may be considered as potential competing interests: Anne Tjoenneland reports financial support was provided by World Cancer Research Fund. Anja Olsen reports financial support was provided by Innovation Fund Denmark. Torben Sisgaard reports financial support was provided by Novo Nordisk Foundation Challenge Programme. Jorg Schullehner reports a relationship with Løgten-Skødstrup Vandværk A.m.b.a. that includes: board membership. Catherine P. Bondonno reports a relationship with a National Health and Medical Research Council Ideas Grant that includes: funding grants. Catherine P. Bondonno reports a relationship with Western Australian Future Health Research and Innovation Fund that includes: funding grants. If there are other authors, they declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper.

Are source-specific nitrate/nitrite intakes associated with colorectal cancer?

Study design: Cohort study – Prospective cohort (Danish Diet, Cancer and Health), source-specific nitrate/nitrite and colorectal cancer
Population: Danish adults
Country: Denmark
Period: 27 years follow-up
Sample size: 54,610 (2,245 CRC cases)
Inclusion and exclusion criteria: not stated in abstract

Exposure / intervention: Plant, animal, processed-meat and tap-water nitrate/nitrite
Comparator: Q1
Endpoints: Colorectal cancer and subtypes
Statistical methods: Cox models; stratified analyses

Results: No associations between nitrate/nitrite from plant, natural animal or additive-permitted meat sources and CRC. Tap-water nitrate Q5 vs Q1 associated with distal colon cancer HR 1.48 (1.11-1.97); tap-water nitrate >=9.25 mg/L vs <1.27 mg/L: colon cancer HR 1.52 (1.11-2.07).
Absolute risks: not reported
Authors' conclusion: Nitrate/nitrite from food sources were not associated with CRC; higher tap-water nitrate was associated with distal colon and colon cancer.

Tap-water association CI log-symmetric; subsite finding needs replication.

No cancer signal for vegetable nitrate.

Ward 2010 (thyroid).

European.

Contradicts harm from vegetable nitrate; drinking water is a separate issue.

Multidimensional assessment
Multidimensional assessment
Authenticity of the source	verified
Methodological quality	moderate
Risk of bias	some concerns
Precision of results	moderate
Directness	direct
Reproducibility	unknown
Consistency with the overall evidence	consistent
Regional transferability	high
Adequacy of the interpretation (by the archive)	not applicable

Replication.