Dose-response meta-analysis of ultra-processed food with the risk of cardiovascular events and all-cause mortality: evidence from prospective cohort studies

Background: Previous meta-analyses included abundant cross-sectional studies, and/or only assessed high versus low categories of UPF consumption. We conducted this meta-analysis based on prospective cohort studies to estimate the dose-response associations of UPF consumption with the risk of cardiovascular events (CVEs) and all-cause mortality among general adults. Methods: PubMed, Embase, and Web of Science were searched for relevant articles published up to August 17, 2021, and newly published articles between August 17, 2021 and July 21, 2022 were re-searched. Random-effects models were used to estimate the summary relative risks (RRs) and confidence intervals (CIs). Generalized least squares regression was used to estimate the linear dose-response associations of each additional serving of UPF. Restricted cubic splines were used to model the possible nonlinear trends. Results: Eleven eligible papers (17 analyses) were finally identified. The pooled effect size for the highest versus lowest category of UPF consumption showed positive associations with the risk of CVEs (RR = 1.35, 95% CI, 1.18-1.54) and all-cause mortality (RR = 1.21, 95% CI, 1.15-1.27). For each additional daily serving of UPF, the risk increased by 4% (RR = 1.04, 95% CI, 1.02-1.06) for CVEs and 2% (RR = 1.02, 95% CI, 1.01-1.03) for all-cause mortality. With increasing UPF intake, the risk of CVEs reflected a linear upward trend (P-nonlinearity = 0.095), while all-cause mortality reflected a nonlinear upward trend (P-nonlinearity = 0.039). Conclusion: Our findings based on prospective cohorts suggested that any increased level of UPF consumption was linked to higher CVEs and mortality risk. Thus, the recommendation is to control the intake of UPF in daily diet.