The first concrete link between football and degenerative brain disease was found in a new study by Boston University researchers that also showed the longer players play the game, the greater the risk of permanent damage.

Jonathan Cherry, lead author of the project, said the study also takes researchers one step closer to early diagnosis and treatment of the potentially deadly condition.

“That middle step was kind of missing for a while,” said Cherry, a postdoctoral fellow in neurology at Boston University School of Medicine. “Just by knowing there’s a connection, it’s incredibly beneficial so we have a place to start with potential therapies and identifying it early on.”

The findings, published online Friday in Acta Neuropathologica Communications, show a direct correlation between brain inflammation brought on by football-related head injury and chronic traumatic encephalopathy, or CTE.

Brains of 66 professional and collegiate football players, along with 16 non-athlete brains, were examined. Scientists used statistical modeling that strongly connected inflamed brain material to CTE. Researchers went a step further to compare the number of years playing football to the amount of damage in the brain that left players at higher risk of degenerative brain disease.

“We saw that there was a connection there,” Cherry said. “Those who played football longer had more inflammation.”

CTE has been found in the brains of deceased athletes and others with a history of repetitive hits to the head, resulting in concussions. Yet while there has been plenty of conjecture on risk factors, research has yielded few definitive answers.

“It’s been suspected that inflammation has been involved, but there hasn’t been a lot of proof actually linking it to CTE,” Cherry said.

The study coincides with an upcoming announcement from Boston University researchers later this morning about the brain of former Patriots running back Kevin Turner, whose death from ALS last spring at 46 was a suspected consequence of CTE.

Chris Nowinski, a Harvard graduate and co-founder and CEO of the Waltham-based Concussion Legacy Foundation, said Cherry’s study is “the sort of breakthrough that will lead scientists to be able to treat the disease.”

“It bolsters the knowledge that there’s a correlation between length of career and brain damage,” said Nowinski, a former wrestler who said he endured several concussions with lasting consequences. “To be honest, I’m glad my mom held me out of football until high school.”

Funding for this study was provided by the National Institute of Neurological Disorders and Stroke, the National Institute of Aging, the Department of Veterans Affairs, the Alzheimer’s Association and the Concussion Legacy Foundation.