<human>: Provide a brief overview of the text.

I have been a long time lurker of reddit and just recently created an account, any help i could get on this subject would be amazing. I work with a group of girls at a restaurant that are hardcore vegan and astrologist. Although they agree that spaghetti monsters and all other religions are a fallacy, they swear by the astrology symbols and what it tells them.
The astrology argument doesn't bother me too much because I just don't care but when they talk about food i feel as though i am at a westboro baptist church rally against gays.
The problem is not just that they argue about meat; they argue about everything, like whats in tap and bottled water and how detrimental it is to your body, how non organic vegetables and fruit have steroids in them that will give you brain cancer, horse hooves in red wine and everything else you could possible think of. 
Every time I talk with them i find out that i am eating something that will kill me. Does anyone have good arguments to falsify some of these claims or have experience dealing with people like this?
<bot>: My coworkers believe that all food and drink corporations create products that are harmful and will kill you. Do you have any tips on debating or arguing against someone like this?