Pro day at Kent State University means college players from around the region are measured, weighed and tested under the watchful eyes of NFL scouts. Kent State quarterback Spencer Keith is one of the players they’re watching closely, and he's hoping to get picked up by an NFL team. But Keith is not worried about the risk of concussions in the big league. He says it's a concern for a lot of people, "but it’s part of the game." He doesn't admit to ever suffering a concussion in his college carrier, but he's taken his share of hits.

Proteins where they don't belong
And it’s the long-term impact of these more common hits that is the focus of a new study by Cleveland Clinic researchers. Dr. Damir Janigro is the lead author. He says he and his fellow researchers followed a protein called S-100B that’s normally found only in the brain. But when they took blood samples from 67 college football players in the study, he got a surprise. Janigro says in players who had no concussions, but only several "sub-concussive" hits to the head, "S-100 was elevated at the end of the game. It went down to normal levels the day after the game, but it was nevertheless elevated.”

Janigro found that the more hits a player took, the higher the levels of S100 in the blood. "But also, there were changes in the MRI scans that are suggestive of an increased risk of degenerative brain diseases.” In other words, temporary swelling in the brain, but not quite a concussion, could lead to problems down the road when college players, like everyone else, succumb to the effects of aging.

An army of anti-bodies waiting to assault the brain
For now, Janigro is more worried about the presence of the brain protein in the blood, because the body’s immune system doesn’t recognize S100 and therefore builds up antibodies against it. He says numerous studies show that having antibodies against your brain is a risk factor for brain disease. Janigro says repeated hits to the head create a backlog of antibodies waiting to attack the next time there’s damage to tiny blood vessels in the brain. “So, in other words, when your door opens, it’s better if you don’t have an army ready to assault.”

Janigro and his team are working on a blood test for the brain protein S100 that could be given on the sidelines to determine whether a player should sit out for a while or give up the game altogether.

As a native of Italy, Damir Janigro is not a fan of American football, but as a researcher studying the blood-brain-barrier, he can’t think of a better research model.

The Cleveland Clinic study adds weight to a body of research showing that a player using his head as a battering ram, even if it doesn’t cause a concussion, can increase the risk of neuro-degenerative diseases down the road. The research is published in the current edition of the online journal PLOS One.