Send to

Choose Destination
Ann Intern Med. 2019 Oct 1. doi: 10.7326/M19-0622. [Epub ahead of print]

Effect of Lower Versus Higher Red Meat Intake on Cardiometabolic and Cancer Outcomes: A Systematic Review of Randomized Trials.

Author information

McMaster University, Hamilton, Ontario, Canada (D.Z., J.B., K.C., K.M., B.S., Y.L., G.H.G.).
Dalhousie University, Halifax, Nova Scotia, Canada (B.C.J.).
Jagiellonian University Medical College, Kraków, Poland (M.M.B.).
Iberoamerican Cochrane Centre Barcelona, Biomedical Research Institute San Pau (IIB Sant Pau), Barcelona, Spain (C.V., M.R., P.A.).
University of British Columbia, Vancouver, British Columbia, Canada (D.S.).
University of Toronto, Toronto, Ontario, Canada (A.A.).
Clinica Las Americas, Medellin, Colombia (A.M.Z.).
Chosun University, Gwangju, Republic of Korea (M.A.H.).
Netherlands Comprehensive Cancer Organisation (IKNL), Utrecht, the Netherlands (R.W.V.).
Institute of Science and Technology, Universidade Estadual Paulista, São José dos Campos, São Paulo, Brazil (R.E.).



Few randomized trials have evaluated the effect of reducing red meat intake on clinically important outcomes.


To summarize the effect of lower versus higher red meat intake on the incidence of cardiometabolic and cancer outcomes in adults.

Data Sources:

EMBASE, CENTRAL, CINAHL, Web of Science, and ProQuest from inception to July 2018 and MEDLINE from inception to April 2019, without language restrictions.

Study Selection:

Randomized trials (published in any language) comparing diets lower in red meat with diets higher in red meat that differed by a gradient of at least 1 serving per week for 6 months or more.

Data Extraction:

Teams of 2 reviewers independently extracted data and assessed the risk of bias and the certainty of the evidence.

Data Synthesis:

Of 12 eligible trials, a single trial enrolling 48 835 women provided the most credible, though still low-certainty, evidence that diets lower in red meat may have little or no effect on all-cause mortality (hazard ratio [HR], 0.99 [95% CI, 0.95 to 1.03], cardiovascular mortality (HR, 0.98 [CI, 0.91 to 1.06]), and cardiovascular disease (HR, 0.99 [CI, 0.94 to 1.05]). That trial also provided low- to very-low-certainty evidence that diets lower in red meat may have little or no effect on total cancer mortality (HR, 0.95 [CI, 0.89 to 1.01]) and the incidence of cancer, including colorectal cancer (HR, 1.04 [CI, 0.90 to 1.20]) and breast cancer (HR, 0.97 [0.90 to 1.04]).


There were few trials, most addressing only surrogate outcomes, with heterogeneous comparators and small gradients in red meat consumption between lower versus higher intake groups.


Low- to very-low-certainty evidence suggests that diets restricted in red meat may have little or no effect on major cardiometabolic outcomes and cancer mortality and incidence.

Primary Funding Source:

None (PROSPERO: CRD42017074074).


Supplemental Content

Full text links

Icon for Silverchair Information Systems
Loading ...
Support Center