'Concussion' Doctor Changes the Conversation About High-Contact Sports

— -- Will Smith’s passionate performance in the new film “Concussion” earned him a Golden Globe nomination.

The man Smith portrays in the film is Dr. Bennet Omalu, a Nigerian-born forensic pathologist who is credited with being the first person to tie head injuries to the development of chronic traumatic encephalopathy (CTE), a degenerative brain disease caused by repeated blows to the head.

The actor thanked Omalu after learning of his nomination, writing, “I'm grateful to the HFPA for recognizing Dr. Omalu's inspiring and heroic story and I couldn't feel more honored to be included with this group of phenomenal actors. Congratulations, Dr. Omalu. See you at the Globes.”

Omalu was humbled by his message, replying on “Good Morning America” today, “Will Smith is such a wonderful individual. He’s pristine,” said Omalu. “I wish him the best of luck and may peace be with him.”

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Researchers are still working to understand the exact way that CTE develops, but it is a process that seems to involve many factors, including microscopic damage to brain cells that occurs from repeated head trauma. This damage is thought to lead to the buildup of abnormal proteins in the brain – the most notable of which is called tau – that is also found in Alzheimer's patients and is associated with a breakdown of brain tissue. Symptoms include memory loss, confusion, impulse control problems, aggression, depression, anxiety and progressive dementia.

The disease can only be diagnosed after death when tissue samples can be examined for the tau protein.

CTE has been found mostly in athletes who play contact sports, such as football. Omalu’s discovery pitted him against the powerful NFL.

Multiple NFL players – including Frank Gifford and Junior Seau -- have been diagnosed with CTE after their deaths and the league continues to face criticism that it has not done enough to protect players.

“We welcome any conversation about player health and safety,” the NFL wrote to ABC News. “Broader and deeper awareness of these issues will positively impact all athletes. The NFL has made numerous changes to the game to enhance the health and safety of players at all levels of football. These include nearly 40 rule changes in the last decade like strict concussion protocols, better training and sideline medical care. We are seeing measurable results, including a 34 percent decrease in concussions in NFL games since the 2012 season. Additionally, we are funding independent scientific and medical research and the development of better protective equipment to advance further progress. The game continues to change, and the safety of our players remain our highest priority.”

However Omalu says “it’s not about concussions.”