Associations of daily diet-related greenhouse gas emissions with the incidence and mortality of chronic diseases: a systematic review and meta-analysis of epidemiological studies

• Published in: Epidemiology and health Vol. 45; p. e2023011
• Main Authors: Hong, Jee Yeon, Kim, Young Jun, Bae, Sanghyuk, Kim, Mi Kyung
• Format: Journal Article
• Language: English
• Published: Korea (South) Korean Society of Epidemiology 01.01.2023
• Subjects: Animals; Chronic Disease - epidemiology; Cohort Studies; Diet; greenhouse gases; Greenhouse Gases - adverse effects; Greenhouse Gases - analysis; Humans; Incidence; meta-analysis; Mortality; Observational Studies as Topic; Systematic Review; Systematic review; Diet; Greenhouse gases; Mortality; Meta-analysis
• ISSN: 2092-7193; 2092-7193
• DOI: 10.4178/epih.e2023011

Although the entire process extending from food production to dietary consumption makes a large contribution to total greenhouse gas (GHG) emissions, little and inconsistent evidence exists on the epidemiological associations of daily diet-related GHG emissions with chronic disease risk or all-cause mortality. This systematic review and meta-analysis explored the observational epidemiological relationship between daily diet-related GHG emissions and health outcomes, including the risk of chronic diseases and all-cause mortality. Original articles published in English until May 2022 were identified by searching PubMed, Ovid-Embase, Web of Science, CINAHL, and Google Scholar. The extracted data were pooled using both fixed-effects and random-effects meta-analyses and presented as hazard and risk ratios (RRs) with 95% confidence intervals (CIs). In total, 7 cohort studies (21 study arms) were included for qualitative synthesis and meta-analysis. The GHG emissions of dietary consumption showed a significant positive association with the risk of chronic disease incidence and mortality in both fixed-effects and random-effects models (fixed: RR, 1.04; 95% CI, 1.03 to 1.05; random: RR, 1.04; 95% CI, 1.02 to 1.06). This positive association was robust regardless of how daily diet-related GHG emissions were grouped. More strongly animal- based diets showed higher GHG emissions. However, there were only a few studies on specific chronic diseases, and the subgroup analysis showed insignificant results. There was no evidence of publication bias among the studies (Egger test: p=0.79). A higher GHG-emission diet was found to be associated with a greater risk of all-cause mortality.