Switzerland and Australia for example are among top on longevity nation and their diets are not exactly plant based - diet is only one of the factors
EPA omega 3 fatty acid are ONLY available from animal sources - our body can convert ALA omega 3 fatty acids from plant sources to EPA, but conversion ratio is very small to none (depending from person to person)
Ancient gladiators for example ate mostly plant based diet, and they made special potion from ashes and bones due to low calcium and magnesium level in their food
Also iron from plant sources is not that easily absorbed in our body as from animal sources
Etc etc
These are some facts, but you are free to believe in anything you want
As for ethical reasons, here is pretty good article from nattyornot site
http://nattyornot.com/vegans-and-meat-eaters-are-both-unethical-so-shut-the-fuck-up/
Here I will stop my writing - because arguing with vegan is like arguing with religious fanatic -well..speaking of a sect or a cult
EPA omega 3 fatty acid are ONLY available from animal sources - our body can convert ALA omega 3 fatty acids from plant sources to EPA, but conversion ratio is very small to none (depending from person to person)
Ancient gladiators for example ate mostly plant based diet, and they made special potion from ashes and bones due to low calcium and magnesium level in their food
Also iron from plant sources is not that easily absorbed in our body as from animal sources
Etc etc
These are some facts, but you are free to believe in anything you want
As for ethical reasons, here is pretty good article from nattyornot site
http://nattyornot.com/vegans-and-meat-eaters-are-both-unethical-so-shut-the-fuck-up/
Here I will stop my writing - because arguing with vegan is like arguing with religious fanatic -well..speaking of a sect or a cult