Mortality
Plant protein is linked with living longer, and animal protein is not
12%Lower all-cause mortality for vegetarians in AHS-2
In large studies, vegetarians have lower death rates than meat-eaters[1]. Swapping animal protein for plant protein is linked with living longer, especially when it replaces red meat and eggs[2][3][4]. If you want to live longer, you would stop eating animals.
What the evidence says
The main points first. Every claim is tied to a source below.
Among Adventists, vegetarians had a lower death rate than meat-eaters
Orlich and colleagues followed 73,308 Adventists, and those eating vegetarian diets had 12% lower death rates from all causes than the meat-eaters, and pesco-vegetarians had the lowest rate of all[1]. For vegans the hazard ratio was 0.85, but its confidence interval just included 1.0, so that result on its own wasn’t statistically significant[1]. The biggest drops were in deaths from heart, kidney, and endocrine disease, and the effect was stronger in men[1]. Adventists already smoke less, and even among them, leaving meat off the plate made a difference[1].
Read full article →Eating more animal protein was linked with more deaths, and more plant protein with fewer
Song and colleagues followed U.S. nurses and male health professionals for decades[1]. Those who ate more animal protein, especially from red meat, had higher death rates, and those who ate more plant protein had lower ones[1].
Read full article →Swapping animal protein for plant protein was linked with fewer deaths
Huang and colleagues used the NIH-AARP study to estimate what happens when people replace animal protein with plant protein[1]. The swap was linked with about 10% lower death rates overall, in both men and women, and the drop was bigger when the protein being replaced came from eggs or red meat[1]. Since the benefit comes from the swap itself, there’s no reason to stop at swapping a little[1].
Read full article →Big pooled studies link more plant protein with fewer deaths
Naghshi and colleagues pooled data on 715,128 people and found plant protein linked with lower death rates from all causes and from cardiovascular disease, and the more plant protein people ate, the fewer deaths there were[1]. Animal protein showed no such protection[1]. Dinu’s pooled estimate for vegans’ all-cause mortality was 0.88, from two cohorts that both leaned toward lower risk, but the interval was wide, so that question is still open[2]. The Rotterdam Study and other pooled cohorts found the same: more plant protein, lower all-cause and cardiovascular mortality, and no matching benefit from animal protein[3]. In studies of older adults, swapping animal protein for plant protein was linked with lower cardiovascular mortality and less type 2 diabetes[4].
Read full article →Eating more than 300 g of chicken and turkey flesh a week was linked with more deaths
In a competing-risk analysis, people who ate more than 300 g of chicken and turkey flesh a week had higher death rates from all causes and from gastrointestinal cancers[1]. So switching from cow flesh to chicken flesh doesn’t help; leaving animals off the plate does.
Read full article →Articles
Plant protein is linked with a longer life, and animal protein is not
In pooled data on 715,128 people and in large U.S. studies, people who ate more plant protein had lower death rates from all causes and from heart disease. Animal protein showed no such benefit, and eggs and animal flesh were linked with more deaths.
Read full article →
Sources
Papers and datasets. Each card keeps its caveats, including small samples and single-animal cases.
[1]JAMA Internal Medicine, 2013 · Observational
Vegetarians in the Adventist Health Study-2 had 12% lower mortality
Orlich and colleagues followed 73,308 Adventists and found that vegetarians as a group had 12% lower all-cause mortality than nonvegetarians (HR 0.88), with hazard ratios of 0.85 for vegans (CI 0.73–1.01) and 0.81 for pesco-vegetarians. The links were clearest for cardiovascular, kidney, and endocrine deaths, and stronger in men. The study is observational, and Adventists already tend not to smoke.
[2]JAMA Internal Medicine, 2016 · Observational
Animal protein was linked with higher mortality and plant protein with lower
Song’s team used decades of data from the Nurses’ Health Study and the Health Professionals Follow-up Study. People who ate more animal protein had higher mortality, especially if they already had a risk factor, while more plant protein was linked with lower mortality. Most of the extra risk came from red meat.
[3]JAMA Internal Medicine, 2020 · Observational
Swapping animal protein for plant protein was linked with about 10% lower mortality
Huang’s analysis of the NIH-AARP study found that replacing animal protein with plant protein was linked with about 10% lower overall mortality in both men and women. They measured the swap in steps of 3% of energy, which is a unit of measurement, not a suggested stopping point. The drop was larger when the animal protein being replaced was eggs or red meat.
[4]BMJ, 2020 · Meta-analysis
More plant protein was linked with fewer deaths in 715,128 people
Naghshi and colleagues pooled studies covering 715,128 people and found plant protein linked with lower all-cause and cardiovascular mortality, and the more plant protein people ate, the fewer deaths there were. Animal protein didn’t show that protection.
[5]Critical Reviews in Food Science and Nutrition, 2017 · Meta-analysis
Vegetarians had less heart disease and cancer in Dinu’s meta-analysis
Dinu’s meta-analysis linked vegetarian diets with fewer cases of ischemic heart disease and cancer. For vegans, all-cause mortality pooled at a relative risk of 0.88, in line with AHS-2, but that came from only two cohorts with a wide interval, so the question isn’t settled.
[6]Nutrients · Observational
Eating over 300 g of chicken and turkey flesh a week was linked with a higher risk of death
In a competing-risk analysis, eating more than 300 g of chicken and turkey flesh a week was linked with higher death rates from all causes and from gastrointestinal cancers.
[7]European Journal of Epidemiology, 2020 · Meta-analysis
Plant protein was linked with fewer deaths in the Rotterdam Study and pooled cohorts
Combining the Rotterdam Study with a meta-analysis of other cohorts, the researchers found that higher plant protein intake was linked with lower all-cause and cardiovascular mortality. Animal protein didn’t show the same benefit, and the authors see the results as support for shifting protein from animals to plants.
[8]Nutrients, 2022 · Review
In older adults, swapping animal for plant protein was linked with fewer cardiovascular deaths
A systematic review of substitution studies in older adults found that swapping animal protein for plant protein was linked with lower cardiovascular mortality and less type 2 diabetes.