Leaving football was the most difficult decision of Shane DiBona’s young life.

A member of the Duxbury High School (DHS) class of 2009, he was a standout on the football field, leading his team to a 13 – 0 season and Division 2A Super Bowl title. Picked up by the University of Iowa’s Division I Hawkeyes, he was a star lineman with the potential to go pro until a few weeks ago when he took a hit during a non-contact practice that changed everything. “A month and a half ago, we started spring ball,” said DiBona in a phone interview from the campus of the University of Iowa. “I took a wicked shot under the jaw. It was helmet to helmet. I got whiplash and my head hit the ground.”

It wasn’t a critical bout with rhabdomyolysis, a torn Achille’s tendon or shoulder surgery that forced his hand. It was his fourth concussion in four years that made DiBona consider his health.

Researchers at Boston University’s Center for the Study of Traumatic and Encephalopathy (BUCSTE) and the Department of Veteran’s Affairs established a link between football and neurodegenerative diseases such as chronic traumatic encephalopathy (CTE), a form of dementia, and amyotrophic lateral sclerosis ALS, also know as Lou Gehrig’s Disease. Knowing this, DiBona chose his future health over football.

“I’m looking at a life with multiple blows to the head,” said DiBona. “I’m more concerned with my life 30 years down the road when I have a family and kids.”

He’s right to be concerned. The National Football League (NFL) is currently being sued by 100 players who claim the league didn’t protect them from concussions during pro games. Former New Orleans Saints safety Steve Gleason, 34, announced last fall he was diagnosed with ALS. He is among 27 known NFL players to go public with such a diagnosis. Then there are the suicides. Last year, Chicago Bears’ Dave Duerson shot himself in the chest after sending loved ones a text asking that his brain be donated to BUCSTE. Researchers there confirmed he suffered from CTE. And just last week, former New England Patriot Junior Seau also shot himself in the chest. His family recently announced his brain will be studied for signs of CTE.

According to Dr. Janet Kent, director of the Sports Concussion Clinic at South Shore Hospital, there’s no predicting who will be affected by head injuries or even the number and severity of concussions that can cause CTE.

“Young athletes have a risk of loss of cognitive function after multiple concussions. There does not seem to be a particular number of concussions that puts an athlete at risk,” said Dr. Kent. “It’s different for each athlete. For some, one or two is too many, for others three or four don’t appear to cause long-term problems.”

For DiBona, his most recent concussion was unlike the previous three. Though the Iowa football team trainers put him through the tests right away, DiBona didn’t initially notice any issues. Within days, however, he realized he had a problem. He began experiencing headaches, confusion, delayed reaction times, sensitivity to light and those symptoms didn’t go away for a long while.

“A month went by,” said DiBona. “About a week ago, I started to feel better. I could remember my days and what I was doing the day before.”

The decision to leave football, a sport he’s played since he was seven, wasn’t a decision DiBona made on his own. He consulted his coach, the team’s doctors, and perhaps most important, his family. For his mother Faith DiBona, it wasn’t an easy decision, but it was the right one.

“I think of all the injuries, this one scared him the most,” said Faith from her Norwell gift shop, Persimmons. “The others he knew would heal, but this one was scary. I don’t think it was an easy decision. The other issue is we don’t know the cumulative effect (of head injuries). He’s had a helmet on since he was seven.”

DiBona’s coach at the University of Iowa, Kirk Ferentz, said he will miss having the lineman on his team, but that he respects and supports his decision. Football wasn’t designed for the human body, he said. As disappointed as he is as his coach, he knows DiBona must be more so.

“Shane will still get his degree, which is the most lasting effect for any athlete,” said Ferentz. “But the bad news is it’s the end of pursuing something he’s pursued since an early age.”

Like many of his contemporaries, DiBona started playing at seven. When Faith DiBona was asked if she would have discouraged Shane from playing football all those years ago, she rightly points out that the potential side effects of concussions weren’t as well known as they are now.

And yet no one yet knows how far reaching those effects may be. According to Dr. Kent, research on the long-term effects is ongoing.

“Researchers are recently focusing on the effects of multiple hits to the head, even those that do not cause a concussion,” said Dr. Kent. “More research is needed for definitive answers.”

With greater awareness comes better preparation. Duxbury High School football coach Dave Maimaron implemented ImPact testing, which takes a baseline cognition test of athletes pre-concussion to compare to post-concussion, about three or four years ago. It’s a program Maimaron takes seriously. In addition to instituting ImPact testing, he bought new helmets for his team.

“It’s a shame, he had a promising career at Iowa,” said Maimaron. “It’s too bad, but you get only one brain.”

For DiBona, he chooses to focus on the wins and not the losses his decision will afford him. The University of Iowa has given him a medical scholarship to continue his studies; he’ll now be home with his family for Thanksgiving and Christmas instead of playing football, summers too; and, most of all, he has the possibility of a healthy future. It’s a decision he’s at peace with.

“The idea of having a family and a life at 50 is more important than having a short-term career at the highest level,” said DiBona. “People see athletes as people who go until they can’t anymore. But if you take a step back, it’s not really worth it.”