Digestery
Diet and food › Red Meat, Cancer and the Heart › Studies

Pooled review (meta-analysis)

Pooled review of 148 studies: red and processed meat linked to more cancers

Farvid and colleagues · European journal of epidemiology · 2021

Original title: Consumption of red meat and processed meat and cancer incidence: a systematic review and meta-analysis of prospective studies.

Under review. A person has not yet checked this summary against the paper. It is written from the PubMed abstract. Until a person checks it, search engines are asked not to list this page.

What the study found

Points to harm

Highest red meat intake linked to more breast (RR = 1.09), colorectal (RR = 1.10; 95% CI = 1.03-1.17) and lung cancer (RR = 1.26), among others. Processed meat linked to 18% more colorectal and 6% more breast cancer risk.

The study at a glance

Type of study
Pooled review (meta-analysis)
Who or what was studied
148 studies · Adults in long-term studies that tracked meat eating and later cancer
What was tested
Highest vs lowest group of red meat, processed meat, and both together
What it measured
The question itself: cancer, heart disease and death
Who has a stake
No disclosure in PubMed
No disclosure in PubMed.
Journal
European journal of epidemiology, 2021
Source
PubMed record 34455534. This page is based on the abstract only.

How much this study counts

  • ✓Pools the results of 148 studies.
  • •A pooled review is only as strong as the studies it pools.
  • ✓Measured the question itself: cancer, heart disease and death.
  • •The PubMed record has no conflict-of-interest statement.
  • •Summarized from the PubMed abstract only. The full paper may hold details the abstract leaves out.

✓ Strength– Limit• Note

These points come from fixed rules about the type of study, its size and length, what it measured, and who has a stake. Every study on Digestery gets the same rules.

Where this study sits

This paper is not on the ladder. It is a pooled review (meta-analysis), and reviews and opinion pieces discuss studies that are already counted on the steps below.

↑ Stronger evidence

  1. Trials in people: cancer and heart disease

    0

    Not done yet. This is the step that would answer the question.

  2. Trials in people: other measures

    0

    None among the papers we read.

  3. Trials in people: lab tests or safety

    6

    2 benefit, 4 harm

  4. Population studies

    12

    1 benefit, 2 mixed, 1 no difference, 8 harm

  5. Blood levels and genes

    0

    None among the papers we read.

↓ Weaker evidence

  • Points to benefit
  • Mixed
  • No difference
  • No direction
  • Points to harm

How it fits with the other research

The short answer to “Does red meat raise cancer and heart disease risk?”

Linked to higher risk, especially processed meat.

Confidence: low. Based on 30 on-topic papers.

Read the full answer
  • Part of the finding “Bowel cancer links are the most consistent”.
  • Summed up in “What reviews found”: Pooled 148 published articles on cancer. High red meat went with more breast, endometrial, colorectal, lung and liver cancer; high processed meat with more breast, colorectal and lung cancer.
  • Open item for a person: Meta-analyses Farvid 2021, Ungvari 2025, Huang 2021 and Shi 2023 likely share cohorts, so their results are not independent.
  • Open item for a person: 16 relevant papers have no conflict statement in PubMed, including the large meta-analyses Farvid 2021 and Huang 2021.

Other reviews on this question

See all 30 studies on this question

How this page was made

Label

First read of the abstract
Claude Sonnet
Independent second read
Claude Haiku
Differences settled
The reviewer corrected 2 fields after reading the abstract. Claude Opus 5.5.
Headline
Claude Sonnet, from the checked study record. A script checked its numbers and wording.
Numbers
Checked against the abstract by a script
“How much this study counts”
Fixed rules, the same for every study
Source check by a person
Not yet. Required before search engines may list this page.

Spot an error? Email a flag with a link to your source, or use the form on the question page.