Egg Consumption and Risk of All-Cause and Cause-Specific Mortality: A Systematic Review and Dose-Response Meta-Analysis of Prospective Studies

Abstract

The association between egg consumption and mortality is extremely debatable. This study aimed to investigate the potential dose-response association of egg consumption with risk of mortality from all-causes and cause-specific in the general population. The primary comprehensive literature search was conducted in PubMed/Medline, Scopus, ISI Web of Science, and Embase up to March 2021, as well as reference lists of relevant original papers and key journals. We calculated summary relative risks (RR) and their 95 confidence intervals (CIs) for the highest and lowest categories, as well as the linear trend estimation of egg intake, using the random effects model. Thirty-three (32 publications) cohort studies were included. These studies enrolled 2,216,720 participants and recorded 232,408 deaths from all causes. Comparing highest vs. lowest egg intake categories was not associated with the risk of mortality from all-causes (RR: 1.02; 95 CI: 0.94 to 1.11, n =25), CVD (RR:1.04; 95 CI: 0.87 to 1.23, n =11), CHD (RR: 0.98; 95CI: 0.84 to 1.16, n =10), stroke (RR: 0.81; 95CI: 0.64 to 1.02, n=9), and respiratory disease (RR: 0.96; 95 CI: 0.53 to 1.71, n =3); however, it was associated with a higher risk of cancer mortality (RR: 1.20; 95CI: 1.04 to 1.39, n =13). In the linear dose-response analysis, an additional one egg intake per week was associated with a 2 and 4 increased risk of all-cause and cancer mortality, respectively, and a 4 decreased risk of stroke mortality. The certainty of the evidence was rated as low to moderate. Higher egg consumption was not associated with an increased risk of mortality from all-causes, CVD, CHD, stroke, or respiratory disease, whereas an elevated risk was observed for cancer mortality. These findings suggested that eggs be consumed in low to moderate amounts (up to one egg/d) as part of a healthy diet.