Playing football "destroys players' brains," according to veteran sportscaster Bob Costas, speaking at a sports symposium Nov. 7.

"You cannot change the nature of the game," said Costas, who personalized his comments. "I certainly would not let, if I had an athletically gifted 12- or 13-year-old son, I would not let him play football."

Costas' view of the injury risk to football players dovetails with that of Dr. Bennet Omalu, who Will Smith portrayed in the 2015 film "Concussion." Omalu's memoir, "Truth Doesn't Have a Side: My Alarming Discovery about the Danger of Contact Sports," amplifies the arc of that journey and its broader impacts.

Chief medical examiner of San Joaquin County, Calif., and a clinical professor at the UC Davis School of Medicine, Omalu shares how in 2002, while employed at the Allegheny County (Pa.) medical examiner's office, he performed an autopsy of "Iron" Mike Webster, former center for the Pittsburgh Steelers, dead at age 50. The Hall of Fame player's life had spiraled downward after leaving the game, and the mystery of his decline flummoxed family and friends.

Omalu found trauma to tau protein, which supports and transports nutrients to and from brain cells and fiber. Scores of repeated head strikes from football linemen and linebackers while Webster blocked them had fractured the skeleton of his brain cells and fiber, Omalu surmised. During a months-long investigation, he discovered an incurable brain condition, chronic traumatic encephalopathy (CTE).

In 2005, Omalu published a peer-reviewed paper on this case in the journal Neurosurgery. The NFL accused him of bogus research and denied a connection between football and CTE in players. The league did not stop there. It lobbied scientific journals to reject Omalu's research papers.

To say that such treatment shocked him understates the case, but Omalu's Roman Catholic faith helped him stand his ground against such a formidable foe.

The NFL, a decade later, finally conceded the link between CTE and football. Costas' comments reflect that certainty. It is now what we might call common sense, but that was not the case just a few years ago.

An immigrant from Nigeria, born during its brutal civil war that made him a malnourished infant, Omalu details his life story before the David-and-Goliath struggle with the NFL to amplify his findings on head trauma and football. This immigrant tale in his memoir is nothing short of inspiring, and it's clear that Omalu adores the United States.

However, that affection does not prevent Omalu from holding sports to account for safety reasons. He advises young athletes to avoid high-impact and high-contact sports — boxing, football, ice hockey, mixed martial arts, wrestling and rugby — that put them at risk of head trauma.

Currently, he is on a mission to protect youth from this trauma that causes permanent brain injuries. To achieve prevention, he advocates education Omalu's father, who stressed education, would be proud.

In his book, Omalu addresses parents, a tactic that Costas also takes. Allowing children "to engage in these contact sports," Omalu writes, exposes "him or her to the risk of permanent brain damage, which can manifest as CTE."

This clashes with the sports status quo that high-profile folks such as Costas echo now. Omalu's pioneering efforts made that clarity possible. In ways big and small, through sheer perseverance that truth shall prevail, he paved the path for an ongoing national conversation about reducing the risk of head trauma in sports.