Red and Processed Meat Consumption and Risk for All-Cause Mortality and Cardiometabolic Outcomes: A Systematic Review and Meta-analysis of Cohort Studies.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of observational cohort studies
PubMed 31569213 · doi:10.7326/M19-0655
What was done
Authors conducted a systematic review and meta-analysis of cohort studies with at least 1,000 adult participants to evaluate associations between unprocessed red meat and processed meat intake and all-cause mortality, cardiometabolic outcomes, quality of life, and diet satisfaction. Multiple databases were searched through April 2019 without language restrictions. Data extraction and risk of bias assessments were performed independently by two reviewers, and evidence certainty was evaluated using GRADE.
What was found
Across 61 articles representing 55 cohorts and over 4 million participants, no studies addressed diet satisfaction or quality of life. Low-certainty evidence showed that reducing unprocessed red meat consumption by 3 servings per week was associated with very small reductions in cardiovascular mortality, stroke, myocardial infarction (MI), and type 2 diabetes. Low-certainty evidence also indicated that reducing processed meat by 3 servings per week was associated with very small reductions in all-cause mortality, cardiovascular mortality, stroke, MI, and type 2 diabetes. Specific numeric effect estimates (such as relative risks or hazard ratios) were not reported in the abstract.
Why it matters
This review demonstrates that the absolute epidemiological associations between red or processed meat intake and major cardiometabolic endpoints are very small and underpinned by low-certainty evidence, questioning strong dietary restrictions.
Limits
The included studies were observational cohorts susceptible to residual confounding, inadequate adjustment for known confounders, and recall bias from dietary measurement methods. Additionally, quality of life and diet satisfaction outcomes were unmeasured across all included cohorts.
Cited by
- supports Epidemiological evidence shows that red meat consumption, particularly processed red meat, is associated with adverse cardiovascular outcomes and decreased life expectancy.