Effect of red meat consumption on cardiovascular risk factors: A systematic review and Bayesian network meta-analysis of randomized controlled trials

Background & aims: The role of red meat in cardiovascular risk remains controversial. The aim of this systematic review and Bayesian network meta-analysis (NMA) of randomized controlled trials (RCTs) was to investigate the effects of red meat consumption on cardiovascular risk factors concerning different comparison foods. Methods: A systematic search of RCTs was conducted from the inception to April 2024. Studies compared diets containing red meat to those replacing red meat with various foods. Comparison diets were classified into high-quality plant protein sources, animal protein, mixed animal and plant protein and carbohydrates. The effects of the dietary interventions on cardiovascular parameters were evaluated using a random-effects NMA, with an analysis of interactions between the intervention and control groups. The outcomes were the mean changes in blood lipids, blood pressure, and C-reactive protein (CRP) in the red meat group compared to the comparator group. Results: Thirty-six RCTs were included in the analysis. Consuming plant proteins resulted in a greater reduction in total cholesterol (TC) levels (mean difference (MD) = −0.14; 95 % credible interval (CrI): −0.28 to −0.001, p < 0.05) and low-density lipoprotein cholesterol (LDL-C) levels (MD = −0.19; 95 % CrI: −0.36 to −0.03, p < 0.05) compared to red meat interventions. In contrast, interventions combining animal and plant proteins increased TG levels more than red meat interventions (MD = 0.21; 95 % CrI: 0.06 to 0.34, p < 0.05). The certainty of the evidence for all outcomes ranged from very low to low. Conclusion: The findings of this NMA indicate that the effect of red meat on cardiovascular risk factors depends on the comparison food. Replacing red meat with plant protein sources was associated with favorable changes in TC levels and LDL-C. Registry and registry number for systematic reviews or meta-analyses: CRD42024537865https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42024537865.