Does vegetarianism affect life expectancy? Is an average vegetarian supposed to live longer just because of their diet?

  • related: skeptics.stackexchange.com/q/1790
    – Lior
    Commented Apr 29, 2017 at 18:11
  • 1
    Are you asking about lacto-ovo vegetarians, or some other group?
    – Nic
    Commented May 14, 2018 at 17:24
  • There are many factors involved in a person's life expectancy other than his/her diet which could radically change the results of a scientific evaluation of people's life expectancy. In my opinion the best scientific test for people's life expectancy could be to create a rule-book for everyone to eat the same diet based upon the diet of a person with the highest or most desirable life expectancy. Those who would follow the rule-book could live until they are very old. Commented Nov 22, 2018 at 19:45
  • I am currently researching telomeres and the gut microbiome. I'm by no means an expert at this point, but from what I understand, vegetables contribute to longer telomeres and a healthier gut microbiome (typically reducing risk of cancer and increasing that chance of a longer life), while meats often do the opposite. Perhaps an expert will be able to contribute an answer with more details. Commented Dec 10, 2019 at 4:34

3 Answers 3


Yes, according to a paper by the American Society for Clinical Nutrition. (NIH link here)

Results: Our review of the 6 studies found the following trends: 1) a very low meat intake was associated with a significant decrease in risk of death in 4 studies, a nonsignificant decrease in risk of death in the fifth study, and virtually no association in the sixth study; 2) 2 of the studies in which a low meat intake significantly decreased mortality risk also indicated that a longer duration (≥ 2 decades) of adherence to this diet contributed to a significant decrease in mortality risk and a significant 3.6-y (95% CI: 1.4, 5.8 y) increase in life expectancy; and 3) the protective effect of a very low meat intake seems to attenuate after the ninth decade. Some of the variation in the survival advantage in vegetarians may have been due to marked differences between studies in adjustment for confounders, the definition of vegetarian, measurement error, age distribution, the healthy volunteer effect, and intake of specific plant foods by the vegetarians.


  1. less meat = less risk of death,
  2. less meat for a longer time = an average of a 3 year longer lifespan + less risk of death,
  3. after 90 years of no meat it stops decreasing your risk of death.

Conclusion: Current prospective cohort data from adults in North America and Europe raise the possibility that a lifestyle pattern that includes a very low meat intake is associated with greater longevity.

So yes, scientific research says that vegetarianism could help you live longer, but it primarily decreases your risk of death. (i.e. you might not live to 105, but you probably won't die at 55)

  • 2
    What is the difference between decreasing the risk of death and increasing life expectancy? I'm not sure I understand. Commented Feb 3, 2017 at 20:26
  • @Azor-Ahai I assume that the risk of death counts only health/diet related issues, not death in a car accident and similar. Versus the life expectancy factoring accidental and unrelated deaths in.
    – Riker
    Commented Feb 3, 2017 at 21:48
  • @Riker There is one factor that you didn't consider: A higher percentage of vegan/vegetarian people are privileged or educated than are meat eaters. It's certainly not as common for lower class or impoverished people to be fussy about what they eat, than high-class people living in affluent neighborhoods with a choice of modern food stores and restaurants. Don't you think that this might have an effect on the study results? Commented Mar 15, 2017 at 15:00
  • @marco hm, good point. Can't edjt right now but will later.
    – Riker
    Commented Mar 15, 2017 at 18:23
  • Without looking at these studies closely this can't be considered an acceptable answer.
    – Yola
    Commented Jan 26, 2019 at 12:50

I just read through everybody's comments on this highly significant life/death question. My observation is that the high number of influencing variables will skew the conclusion of any study. With only a small percentage of the total population being vegetarian, having no prevalent marker to identify who they are, a conclusion can't be drawn that group either. Populations that have a significant vegetarian count may also have other factors that skew the interpretation as to why they die when they do.

So far, now a vegetarian myself for over 35 years, my conclusion is that being a vegetarian will add to my life expectancy. That's just because I feel good about what I eat (most of the time). I'm not relying on any study for that feeling but do take into account the endless info-snippets that I am bombarded with from my family and friends. There I have drawn my own conclusion which is that no good can come from eating meat. Add, that the no-meat diet that just feels good and extends to my overall life style and healthy, or not, decision making.

So to answer the question, I'll draw an analogy to what my stock broker tells me about investing, "If it feels good then go with your gut". There's probably a lot of underlying reasons for those feeling and I believe your gut feel is major in answering this question too.

  • Your observation is valid but in this form does not answer the question.
    – istepaniuk
    Commented Jun 17, 2019 at 14:34

I would suggest watching Game Changers and Swapping Knives for Forks on Netflix. They both cite lots of studies confirming extra longevity and decreased risk of disease and cancer from vegetarian and vegan lifestyles.

  • 3
    Colin, you could improve this answer by directly citing the studies mentioned in either of those two documentary movies. A movie is an external resource just like a link to a website. A good answer provides context along with links.
    – Nic
    Commented Dec 3, 2019 at 1:44
  • I didn't provide links, someone edited them in. I don't feel doing their homework for them would be as helpful as pointing them to the right section of the media world to start their education. Commented Dec 3, 2019 at 9:08
  • 3
    @ColinEllis pedagogical theory aside, it is helpful to describe some of the studies for those of us who may want to start with the studies themselves, rather than watching two films and noting them ourselves. A good answer provides information rather than simply directing our users to read elsewhere. (Please see How to Answer).
    – Erica
    Commented Dec 5, 2019 at 22:57

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