Red and processed meat intake and risk of cardiovascular disease: A two-sample Mendelian randomization study.

Background & Aims: Previous observational studies have yielded inconsistent findings regarding associations between red/processed meat intake and the risk of cardiovascular disease (CVD). Some studies have suggested positive relationships, while others have demonstrated no significant associations. However, causal effects remain uncertain. This 2023 Mendelianrandomization (MR) study investigated the causal relationship between red and processed meat (porkmeat, mutton meat, beef meat)intake and CVD risk by analyzing summary data from the UK Biobank (exposure), CARDIoGRAMplusC4D (coronary artery disease [CAD]), MEGASTROKE (stroke), Nielsen et al. (atrial fibrillation [AF]), HERMES (heart failure [HF]), and FinnGen (cardiovascular outcomes) public databases.

Methods: Genome-wide association studies (GWAS) of red meat (pork, beef, and mutton) and processed meat were sourced from the United Kingdom (UK) Biobank. GWAS data on CVD for this study were obtained from the Gene and FinnGen consortia. The primary method employed for the two-sample MR analysis was inverse variance weighting (IVW). Sensitivity analysis was performed to assess the reliability and consistency of the results.

Results: Genetically predicted red and processed meat consumption did not demonstrate a causal association with any CVD outcomes when employing the IVW method. For processed meat intake, the odds ratios (ORs) (95% confidence intervals CIs) in large consortia were as follows: 0.88 (0.56-1.39) for CAD, 0.91 (0.65-1.27) for AF, 0.84 (0.58-1.21) for HF, and 1.00 (0.75-1.05) for stroke. In FinnGen, the ORs were as follows: 1.15 (0.83-1.59) for CAD, 1.25 (0.75-2.07) for AF, 1.09 (0.73-1.64) for HF, and 1.27 (0.85-1.91) for stroke. For beef intake, the ORs (95% CIs) in large consortia were as follows: 0.70 (0.28-1.73) for CAD, 0.85 (0.49-1.49) for AF, 0.80 (0.35-1.83) for HF, and 1.29 (0.85-1.95) for stroke. In FinnGen, the ORs were as follows: 2.01 (0.75-5.39) for CAD, 1.83 (0.60-5.56) for AF, 0.80 (0.30-2.13) for HF, and 1.30 (0.62-2.73) for stroke. For pork intake, the ORs (95% CIs) in large consortia were as follows: 1.25 (0.37-4.22) for CAD, 1.26 (0.73-2.15) for AF, 1.71 (0.86-3.39) for HF, and 1.15 (0.63-2.11) for stroke. In FinnGen, the ORs were as follows: 1.12 (0.43-2.88) for CAD, 0.39 (0.08-1.83) for AF, 0.62 (0.20-1.88) for HF, and 0.60 (0.21-1.65) for stroke. For mutton intake, the ORs (95% CIs) in large consortia were as follows: 0.84 (0.48-1.44) for CAD, 0.84 (0.56-1.26) for AF, 1.04 (0.65-1.67) for HF, and 1.06 (0.77-1.45) for stroke. In FinnGen, the ORs were as follows: 1.20 (0.65-2.21) for CAD, 0.92 (0.44-1.92) for AF, 0.74 (0.34-1.58) for HF, and 0.75 (0.45-1.24) for stroke. The results remained robust and consistent in both the meta-analysis and supplementary MR analysis.

Conclusions: This MR study demonstrated no significant causal relationships between red/processed meat intake and the risk of the four CVD outcomes examined. Further investigation is warranted to confirm these findings.