Oscar-nominated US actor Will Smith hopes his new film "Concussion" will help raise awareness among parents of the long-term health risks posed by American football.

"For me more than anything, I'm a football dad," Smith said late Tuesday as he attended the premiere of the hard-hitting sport drama.

"I love football. For me, this is about informing parents and delivering the truth and people will decide what they want to do with that."

"Concussion," which opens December 25, follows Nigerian-born forensic pathologist Bennet Omalu, one of the first to diagnose degenerative brain disease in former players of the National Football League.

The much-anticipated movie is sure to revive an ongoing debate on brain injuries in the most popular and most watched sport in America.

"I watched my son play football for five years and I didn't know. As a parent, I didn't know," said Smith of the degenerative disease that results from repeated blows to the head.

"And I've talked to professional football players and people who have been in the game a long time that don't know the information that is in this film."

Also attending the premiere was Omalu and family members of football players who suffered from CTE, or chronic traumatic encephalopathy.

Omalu, who got a standing ovation at the end of the screening, said he hoped the fact that Hollywood had decided to put his story on the big screen would raise awareness about CTE.

"I thought Hollywood would be the most potent medium to portray the truth," said Omalu, who knew nothing about football when he performed his first autopsy on a retired player while working in Pittsburgh.

Omalu's work was first widely publicized in the 2013 Frontline documentary "League of Denial."