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


  • This article has been corrected. The original version (PDF) is appended to this article as a Supplement. Background: Few randomized trials have evaluated the effect of reducing red meat intake on clinically important outcomes. Purpose: 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 48835 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]). Limitations: 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. Conclusion: 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).

published proceedings

  • Ann Intern Med

author list (cited authors)

  • Zeraatkar, D., Johnston, B. C., Bartoszko, J., Cheung, K., Bala, M. M., Valli, C., ... El Dib, R.

complete list of authors

  • Zeraatkar, Dena||Johnston, Bradley C||Bartoszko, Jessica||Cheung, Kevin||Bala, Malgorzata M||Valli, Claudia||Rabassa, Montserrat||Sit, Daegen||Milio, Kirolos||Sadeghirad, Behnam||Agarwal, Arnav||Zea, Adriana M||Lee, Yung||Han, Mi Ah||Vernooij, Robin WM||Alonso-Coello, Pablo||Guyatt, Gordon H||El Dib, Regina

publication date

  • January 1, 2019 11:11 AM