Associations of dietary protein intake with all-cause, cardiovascular disease, and cancer mortality: A systematic review and meta-analysis of cohort studies

Nutr Metab Cardiovasc Dis. 2020 Jun 25;30(7):1094-1105. doi: 10.1016/j.numecd.2020.03.008. Epub 2020 Mar 17.


Background and aims: The relationships between dietary protein intake and risk of all-cause, cardiovascular disease (CVD), and cancer mortality are still unclear. We conducted a systematic review with meta-analysis of cohort studies to summarize the evidence.

Methods and results: We searched PubMed and Web of Science for relevant studies through February 2020. The associations of total, animal, and plant proteins with all-cause, CVD, and cancer mortality were evaluated. Study-specific relative risks (RR) were pooled using the fixed effect model when no significant heterogeneity was detected; otherwise the random effect model was employed. Twelve cohort studies were eligible for the study. Increased total protein showed no clear association with risk of all-cause, CVD, and cancer mortality. In the stratified analysis by protein sources, higher plant protein intake was associated with a reduced risk of all-cause mortality (highest vs lowest intake: RR = 0.92; 95% CI: 0.88, 0.96; each 3% increment of intake: RR = 0.97; 95% CI: 0.94, 0.99), and may be associated with a reduced risk of CVD mortality (highest vs lowest intake: RR = 0.90; 95% CI: 0.80, 1.01; each 3% increment of intake: RR = 0.95; 95% CI: 0.91, 0.99). Moreover, higher intake of animal protein may be associated with an increased risk of CVD mortality (highest vs lowest intake: RR = 1.11; 95% CI: 1.01, 1.22; each 3% increment of intake: RR = 1.02; 95% CI: 0.98, 1.06).

Conclusion: This study demonstrates that higher plant protein intake is associated with a reduced risk of all-cause and CVD-related mortality. Persons should be encouraged to increase their plant protein intake to potentially decrease their risk of death.

Keywords: Cancer; Cardiovascular disease; Dietary protein; Meta-analysis; Mortality.

Publication types

  • Meta-Analysis
  • Systematic Review

MeSH terms

  • Adult
  • Aged
  • Aged, 80 and over
  • Cardiovascular Diseases / diagnosis
  • Cardiovascular Diseases / mortality
  • Cardiovascular Diseases / prevention & control*
  • Cause of Death
  • Diet, Healthy*
  • Female
  • Humans
  • Male
  • Middle Aged
  • Neoplasms / diagnosis
  • Neoplasms / mortality
  • Neoplasms / prevention & control*
  • Nutritive Value
  • Plant Proteins, Dietary / administration & dosage*
  • Protective Factors
  • Recommended Dietary Allowances
  • Risk Assessment
  • Risk Factors
  • Risk Reduction Behavior*
  • Time Factors


  • Plant Proteins, Dietary