The Study
Dietary intake of total, animal, and plant proteins and risk of all cause, cardiovascular, and cancer mortality: systematic review and dose-response meta-analysis of prospective cohort studies
This study looked at lots of people over many years and found that those who ate more plant-based proteins (like beans and nuts) tended to live longer. But it doesn't prove that eating more plants made them live longer—maybe they also exercised more, smoked less, or ate healthier overall.
Analysis score
Maximum 85 for a systematic review with meta-analysis.
Where the score came from
Scientists looked at lots of people over many years to see if eating more protein from plants (like beans, nuts, and grains) or animals (like meat and dairy) affects how long people live.
Where does this study sit?
Reviews of RCTs (Meta-analyses)
Max 100Randomized Trials
Max 90Reviews of Cohort Studies
Max 85Cohort Studies
Max 72Reviews of Case-Control Studies
Max 63Case-Control Studies
Max 58Cross-Sectional & Case Series
Max 50Expert Opinion
Max 552 / 100
Quality score
Systematic reviews and meta-analyses of cohort studies. They sit above a single cohort study but below a single randomized trial, because the underlying evidence is still observational.
Key takeaways
Summary
Based on the study abstract and findings.
- 1Yes — swapping just a small amount of meat for beans or nuts each day could add up to a meaningful boost in lifespan over time.
- 2People who ate more plant protein lived longer: every extra 3% of their daily calories from plant protein cut their risk of dying by 5%.
- 3Plant protein also lowered heart disease deaths by 12%.
- 4Animal protein didn’t show any clear link to living longer or shorter.
Score breakdown, methodology, conflicts of interest, evidence analysis & raw study data
Publication
Journal
The BMJ
Year
2020
Authors
S. Naghshi, O. Sadeghi, W. Willett, Ahmad Esmaillzadeh
Related Content
Claims (6)
Eating more or less total dietary protein does not change the risk of dying from any cause or from heart disease.
For every 3% increase in daily calories from plant protein, the risk of dying from any cause decreases by 5%.
People who consume more total protein have a 6% lower risk of dying from any cause compared to those who consume less protein.
Eating animal protein does not show a clear connection to increased risk of dying from any cause, heart disease, or cancer when other diet and lifestyle factors are taken into account.
People who consume more plant protein have a lower risk of dying from any cause or from cardiovascular disease compared to those who consume less plant protein. Each increase of 3% of daily calories from plant protein is linked to a 5% lower risk of death from any cause.
Eating plant protein is not linked to lower rates of death from cancer, but it is linked to lower rates of death from heart disease and other causes, meaning its protective effect does not extend to cancer.
Not medical advice. For informational purposes only. Always consult a qualified healthcare professional before making health decisions.