People who eat a strict vegan diet (no meat, dairy, or eggs) may have a slightly lower risk of dying from any cause, especially men, but the evidence is not strong enough to be certain.
Evidence from Studies
No evidence studies found yet.
What Would Prove This
Per GRADE and EBM methodology, here is what ideal scientific evidence would look like to definitively prove or disprove this claim, ordered from strongest to weakest.
A meta-analysis could determine whether vegan diets consistently reduce mortality across multiple cohorts, resolving uncertainty from small subgroup samples.
A systematic review and meta-analysis of at least 8 prospective cohort studies reporting mortality outcomes for vegans versus nonvegetarians, with standardized dietary definitions (no animal products), adjustment for BMI, smoking, and physical activity, and pooled analysis using random-effects models.
A randomized trial could determine whether assigning individuals to a vegan diet directly reduces mortality compared to other diets, isolating the effect of eliminating all animal products.
A double-blind, placebo-controlled trial randomizing 5,000 adults aged 40–70 to either a whole-food, plant-based vegan diet (no animal products, supplemented with B12 and D) or a standard omnivorous diet for 20 years, with primary outcome being all-cause mortality and secondary outcomes including cardiovascular events and cancer incidence.
A cohort study could confirm whether vegan diets predict lower mortality in populations without shared religious or health-conscious norms.
A prospective cohort study following 35,000 adults from general U.S. and European populations, classifying dietary patterns into vegan, vegetarian, and omnivore groups using repeated dietary assessments over 15 years, adjusting for socioeconomic status, education, and health behaviors.
A case-control study could compare past vegan diet adherence between individuals who died prematurely and those who lived longer.
A matched case-control study comparing 1,000 individuals who died before age 70 with 1,000 living controls, using validated dietary recall to reconstruct vegan diet adherence over the prior 20 years, adjusting for age, sex, and socioeconomic status.
A cross-sectional survey could show whether vegans are more likely to be alive than nonvegans, but cannot determine if diet caused survival.
A national survey measuring current dietary patterns and mortality status in 70,000 adults aged 40–80, comparing the proportion of vegans among those who died versus those alive, adjusting for age and sex.