"I've been here for five years and I'm very happy here," he told United's official website. "Sometimes I have had difficult moments at the club, but I've always got through those moments and everyone has always helped me – the manager, my teammates, the staff and the fans.
"I know this is the best club for me. I feel confident and I feel very happy in my life. My family is good and I hope my injuries are now behind me.
"I'm 24 now and I've learnt a lot in the last few years, and I understand that to do well in my career, I have to look after myself and train hard. That is my aim."
Anderson joined United from Porto in 2007.