The star, who announced his second attempt at being vegan last year, made the comments during his Recovery Live Tour 2020.
When asked by an audience member whether he went vegan 'for the animals' or 'part of his spiritual journey', Brand said: "I was nagged into veganism by society... I was vegetarian from when I was a little kid, 14, because of The Smiths and because of like 'oh, they do what in factory farms?'.
"You know, like, it was too brutal. And then my mate Simon Amstell, he's a very good comedian, made a film called Carnage which sort of talked about like in 50 years people will look back and go 'f***ing hell they ate animals'."
'I'm still angry'
The star also cited Kip Anderson's documentary What The Health for turning vegan.
"He showed how the diabetes, heart, and cancer foundation of America were funded by sort of meat and dairy and egg industries, and like they give the advice on what foods are healthy...
"We're not meant to eat any of that. It was all a big f***ing mad coup. So, the reason to become vegan, it was sort of anger actually, thinking about it now. And I'm still angry because I'm f***ing starving."