Characterizing the potential health effects of exposure to risk factors such as red meat consumption is essential to inform health policy and practice. Previous meta-analyses evaluating the effects of red meat intake have generated mixed findings and do not formally assess evidence strength. Here, we conducted a systematic review and implemented a meta-regression—relaxing conventional log-linearity assumptions and incorporating between-study heterogeneity—to evaluate the relationships between unprocessed red meat consumption and six potential health outcomes. We found weak evidence of association between unprocessed red meat consumption and colorectal cancer, breast cancer, type 2 diabetes and ischemic heart disease. Moreover, we found no evidence of an association between unprocessed red meat and ischemic stroke or hemorrhagic stroke. We also found that while risk for the six outcomes in our analysis combined was minimized at 0 g unprocessed red meat intake per day, the 95% uncertainty interval that incorporated between-study heterogeneity was very wide: from 0–200 g d⁻¹. While there is some evidence that eating unprocessed red meat is associated with increased risk of disease incidence and mortality, it is weak and insufficient to make stronger or more conclusive recommendations. More rigorous, well-powered research is needed to better understand and quantify the relationship between consumption of unprocessed red meat and chronic disease.

描述接触红肉等危险因素对健康的潜在影响对于制定卫生政策和实践至关重要。之前评估红肉摄入影响的荟萃分析得出了不同的结果，并且没有正式评估证据强度。在这里，我们进行了系统回顾并实施了元回归（放宽传统对数线性假设并纳入研究间异质性），以评估未加工红肉消费与六种潜在健康结果之间的关系。我们发现，食用未加工红肉与结直肠癌、乳腺癌、2 型糖尿病和缺血性心脏病之间存在微弱的关联。此外，我们没有发现任何证据表明未加工的红肉与缺血性中风或出血性中风之间存在关联。我们还发现，虽然我们分析中的六种结果的风险在每天摄入 0 g 未加工红肉时被最小化，但纳入研究间异质性的 95% 不确定性区间非常宽：从 0–200 gd ^-1 。虽然有一些证据表明，食用未经加工的红肉与疾病发病率和死亡率风险增加有关，但它还很薄弱，不足以提出更有力或更结论性的建议。需要更严格、更有力的研究来更好地理解和量化未加工红肉的消费与慢性疾病之间的关系。