Communities with little to no consumption of meat, like Seventh-Day Adventists, have significantly lower rates of prion disease and Alzheimers.
While it may be nonsense if your goal is solely prolonging life, avoiding meat seems like a relatively easy way to reduce your risk of becoming worthless to society and yourself; virtually everyone can agree that dementia is something to avoid.
Sounds like confounding bias. Seven-Day Adventists abstain from cigarettes, a main contributor to early death. Also any diet that avoids the standard American diet will probably increase your lifespan, even veganism, though probably less so now with all of the processed vegan foods. That has no bearing on whether veganism is an optimal diet for human longevity, it just implies that the standard American diet is a poor diet. If you look at countries with the highest meat consumption - Hong Kong and Australia - they also have the longest lifespan.
https://pubmed.ncbi.nlm.nih.gov/6654568/
“It is concluded that evidence was found for the thesis that abstinence from cigarette smoking is the main factor explaining the low mortality from ischaemic heart diseases among SDAs”
I find it hard to believe there's enough of a population of Seventh-Day Adventists to actually say they have lower rates of prion disease.
Prion disease incidence is 1 to 2 cases per million people per year. You'd have to have millions of 7th day adventists submitting to research to be able to assert that with any confidence.
Vegan is more than avoiding meat. As far as health is concerned, I would put avoiding salmon, eggs, and fermented milk on the "makes your diet less healthy" list. I would be very curious to see a study that said avoiding once a week liver was healthier than having it.
Daily consumption of red meat? Yeah, the jury appears to be tilted against such behavior/habit.
...I mean, they could have stipulated organic fair-trade vegan. That would be nonsense. You can't very well claim veganism isn't a significant dietary choice with knock-on effects to one's health, though (albeit whether those are negative depends on whether and how you deal with the lack of things in your diet that most of us get mainly/entirely from animal products - vitamin B12, iron etc)
Not claiming anyone knows what any effects might be, positive or negative. Unlike the usual kinds of nonsense woo, though, there might actually be effects. That is my entire thesis.
While it may be nonsense if your goal is solely prolonging life, avoiding meat seems like a relatively easy way to reduce your risk of becoming worthless to society and yourself; virtually everyone can agree that dementia is something to avoid.