Los Angeles: Stars like Alicia Silverstone and Brad Pitt have not only given up eating meat, but have also abstained themselves from animal and dairy products like milk and curd.Here's a list of some celebrities who have inculcated a healthy way of living and shown concern for environment by turning vegan, reports eonline.com:Beyonce and Jay Z: The couple recently announced they are going vegan for 22 days ahead of Christmas.Brad Pitt: Although the actor's better half Angelina Jolie was vegan for a long time, she had to give up the lifestyle because she wasn't getting the nutrients she required. Pitt, on the other hand, seems to be doing just fine.Russell Brand: Another vegetarian convert, the British comedian and actor announced his move to veganism via his Twitter page, saying: "I'm now vegan, goodbye eggs."Alicia Silverstone: The "Clueless" actress even started her own website dedicated to the cause - thekindlife.com.Mike Tyson: On why he went vegan, the former boxer said: "I just threw up the white flag. Too many prison cells, jail, too many lawsuits, too many bankruptcies, too many women, too many venereal diseases, too many everything. I got tired."