The association between overall, healthy, and unhealthy plant-based diet indexes and risk of all-cause and cause-specific mortality: a systematic review and dose-response meta-analysis of prospective cohort studies.
Level 3 - non-randomized controlled study
Systematic review and meta-analysis of prospective cohort studies
PubMed 40018753 · doi:10.1039/d4fo04741a
What was done
A systematic review and dose-response meta-analysis searched PubMed, Web of Science, Scopus, and Embase through December 2024 for prospective cohort studies examining associations between plant-based diet indices—overall (oPDI), healthy (hPDI), and unhealthy (uPDI)—and risk of all-cause and cause-specific mortality. Random-effects models were used to calculate relative risks (RRs) and 95% confidence intervals (CIs).
What was found
From 25 prospective cohort studies included: - Adherence to oPDI showed a modest inverse association with all-cause mortality (RR 0.89, 95% CI: 0.83–0.94; n = 15 studies) as well as mortality from cardiovascular diseases, chronic heart disease, and total cancer. - Adherence to hPDI was associated with reduced risk of all-cause mortality (RR 0.86, 95% CI: 0.82–0.90; n = 21 studies), cardiovascular disease, chronic heart disease, total cancer, and prostate cancer mortality. - Adherence to uPDI was associated with higher risk of all-cause mortality (RR 1.20, 95% CI: 1.13–1.27; n = 19 studies), cardiovascular disease, chronic heart disease, and total cancer mortality. - Dose-response meta-analysis demonstrated a monotonic inverse association for oPDI and hPDI, and a positive linear association for uPDI, with all-cause mortality.
Why it matters
This review shows that the association between plant-based eating patterns and reduced mortality depends on diet quality, as diets composed of less healthy plant foods are associated with increased mortality risk.
Limits
All included data derive from observational cohort studies susceptible to residual confounding and self-report dietary bias. Total participant numbers, baseline population demographics, and numerical risk estimates for specific mortality causes were not reported in the abstract.
Cited by
- supports Large-scale meta-analyses and long-term studies show that plant-based diets generally yield better health outcomes than animal-heavy diets.