Red Meat and Processed Meat Consumption and All-Cause Mortality: A Meta-Analysis

High consumption of red meat and processed meat has been associated with increased risk of several chronic diseases. We conducted a meta-analysis to summarize the evidence from prospective studies on red meat and processed meat consumption in relationship to all-cause mortality. Pertinent studies were identified by searching PubMed through May 2013 and by reviewing the reference lists of retrieved articles. Prospective studies that reported relative risks with 95 confidence intervals for the association of red meat or processed meat consumption with all-cause mortality were eligible. Study-specific results were combined by using a random-effects model. Nine prospective studies were included in the meta-analysis. The summary relative risks of all-cause mortality for the highest versus the lowest category of consumption were 1.10 (95 confidence interval (CI): 0.98, 1.22; n 6 studies) for unprocessed red meat, 1.23 (95 CI: 1.17, 1.28; n 6 studies) for processed meat, and 1.29 (95 CI: 1.24, 1.35; n 5 studies) for total red meat. In a dose-response meta-analysis, consumption of processed meat and total red meat, but not unprocessed red meat, was statistically significantly positively associated with all-cause mortality in a nonlinear fashion. These results indicate that high consumption of red meat, especially processed meat, may increase all-cause mortality.