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FactuallyVegan
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Health & Nutrition

Longevity / all-cause mortality

Last reviewed: April 12, 2026

Summary

The evidence for a longevity benefit from plant-based diets is promising but not yet definitive. The widely cited Dinu 2017 meta-analysis found a non-significant trend toward lower all-cause mortality for vegans (RR 0.88, 95% CI 0.75-1.02), though it did find significant reductions in ischemic heart disease and cancer incidence. More recent 2024-2025 meta-analyses have found statistically significant associations: high adherence to a healthy plant-based diet is linked to approximately 14-15% lower all-cause mortality risk (HR 0.85-0.86). Importantly, the quality of plant foods matters — unhealthy plant-based diets (refined grains, added sugars, processed foods) were associated with 20% HIGHER mortality risk. The evidence supports eating more whole plant foods for longer life, but does not yet prove that strict veganism per se extends lifespan compared to other health-conscious dietary patterns.

Supported by 5 cited sources

Key Points

  • 1The Dinu et al. (2017) meta-analysis in Critical Reviews in Food Science and Nutrition is the most widely cited source on vegan diets and mortality. It is essential to report what it actually found: for vegan diets and all-cause mortality, the risk ratio was 0.88 (95% CI 0.75-1.02). Because the confidence interval crosses 1.0, this result is NOT statistically significant — meaning the study could not confirm that vegans live longer. However, Dinu 2017 DID find significant benefits for specific outcomes: reduced ischemic heart disease mortality/incidence (RR 0.75, 95% CI 0.68-0.82) and reduced total cancer incidence (RR 0.92, 95% CI 0.87-0.98).
  • 2More recent meta-analyses have provided stronger evidence. Mo et al. (2025, Frontiers in Nutrition) analyzed 11 cohort studies with 977,763 participants and found that the highest adherence to a plant-based diet index (PDI) was associated with significantly lower all-cause mortality: HR 0.85 (95% CI 0.80-0.90). A healthy plant-based diet index (hPDI) showed similar results: HR 0.86 (95% CI 0.81-0.92). Tan et al. (2024, Frontiers in Nutrition) independently confirmed that high adherence to plant-based diets significantly reduces all-cause, cardiovascular, and cancer mortality.
  • 3A critical nuance: diet QUALITY matters more than strict vegan labeling. Mo et al. (2025) found that an unhealthy plant-based diet index (uPDI — characterized by refined grains, added sugars, fruit juices, potatoes, and sweets) was associated with 20% HIGHER mortality risk (HR 1.20, 95% CI 1.11-1.31). This means a vegan diet built on processed foods and refined carbohydrates may be WORSE for longevity than a health-conscious omnivorous diet.
  • 4The evidence gap between 'plant-based diet' and 'strict vegan diet' matters. Most of the newer meta-analyses measure plant-based diet indices — scores reflecting the proportion of plant foods in the diet — rather than strict vegan self-identification. A diet that is 80-90% whole plant foods may confer most of the longevity benefits without requiring complete elimination of all animal products. The evidence supports 'eat more whole plant foods' more strongly than 'eliminate all animal products.'
  • 5The protective effect appears more pronounced in adults over 55 years old (Tan et al., 2024) and is driven primarily by reductions in cardiovascular and cancer mortality. These are the leading causes of death in high-income countries, so even modest reductions translate into meaningful population-level benefits.

Evidence Summary

Dinu et al. (2017, Critical Reviews in Food Science and Nutrition) conducted a systematic review and meta-analysis finding non-significant all-cause mortality reduction for vegans (RR 0.88, 95% CI 0.75-1.02) but significant reductions in IHD (RR 0.75) and cancer incidence (RR 0.92). Mo et al. (2025, Frontiers in Nutrition) meta-analyzed 11 cohort studies (n=977,763) finding significant all-cause mortality reduction for highest PDI adherence (HR 0.85, 0.80-0.90) and hPDI (HR 0.86, 0.81-0.92), but

...

All evidence is from observational studies subject to residual confounding. People who eat plant-based diets tend to also exercise more, smoke less, drink less alcohol, and have higher socioeconomic status — it is difficult to fully disentangle dietary effects from these lifestyle factors. The Dinu 2017 vegan-specific analysis had wide confidence intervals due to limited vegan-specific data. The newer meta-analyses use plant-based diet indices rather than strict vegan self-identification, so they may not directly address whether strict veganism specifically extends lifespan. Healthy user bias is a persistent concern in nutritional epidemiology. Additionally, most studies were conducted in high-income Western populations and may not generalize globally.

Supporting Evidence

Caveats: Observational confounding and "healthy user bias" are limitations.

Sources:

The Bottom Line

The evidence for a longevity benefit from plant-predominant diets has strengthened considerably between 2017 and 2025, moving from 'suggestive but non-significant' to 'statistically significant in large meta-analyses.' The most robust finding is that eating more whole plant foods and fewer animal products is associated with approximately 14-15% lower all-cause mortality risk. However, the evidence does not yet prove that strict veganism specifically extends lifespan beyond what a health-conscious, plant-heavy flexitarian diet achieves. Diet quality — whole foods vs. processed — matters at least as much as whether the diet is technically vegan.

Practical Takeaways

Focus on whole plant foods: vegetables, fruits, whole grains, legumes, nuts, and seeds. If longevity is your goal, avoid the trap of an 'unhealthy vegan' diet heavy in refined carbohydrates and processed foods — this may actually increase mortality risk. A comprehensive vegan multivitamin addresses potential nutrient gaps (B12, D3, omega-3s) that could undermine the health benefits of a plant-based diet. Do not overstate the evidence — the data supports 'promising and increasingly strong' rather than 'proven and definitive.' The strongest evidence is for eating MORE plants, with diminishing certainty about whether ZERO animal products is necessary for optimal longevity.

Sources & Evidence

5 sources cited across 1 claim

1

Plant-forward diets are associated with lower mortality

Cohort Study

Disclaimer: This content is for informational purposes only and does not constitute medical or nutritional advice. Consult a qualified healthcare professional before making dietary changes.