Pro fighters help scientists understand evolution of concussions

Ladies and gentlemen, let's get ready to rumble.

After a summer of hype, boxing great Floyd Mayweather and MMA star Conor McGregor will lace them up and beat the living daylights out of each other for a purse and audience of millions.

There will be only one winner, but there's some chance that after the fight both fighters will be losers when it comes to one important factor - their neurological health.

Guest host Tim Caulfield spoke with Dr. Charles Bernick, a traumatic brain injury specialist at the Cleveland Clinic in Las Vegas, and the leader of the Professional Fighters Brain Health Study. For the last six years, he's been running a long-term study involving hundreds of fighters to try and better understand the damage they're doing to their brains, and perhaps when they should just say "No Mas."

This interview has been edited for length and clarity.

Tim Caulfield: It seems obvious that an activity that involves repeated blows to the head would result in damage to the brain. What are the big questions that you're trying to answer with the Fighters Brain Health Study.

Dr. Charles Bernick: Well it would seem obvious that everyone would experience some residual brain injury from their exposure to head trauma in boxing or mixed martial arts.

But probably that's not necessarily true. So we know there are certainly people who have been involved in these sports who turn out OK, but we don't know how many. We really don't know what the likelihood of ending up with chronic traumatic encephalopathy, which is a long term complication of head trauma, is. But that's what we're trying to understand is why some individuals can be exposed to head trauma and seem to do fine and others don't and turn out to have dementia, behavioral changes, and mood changes. And these are the questions we're trying to answer.

The whole fight industry was very supportive of this project right from the start.- Dr. Charles Bernick, Cleveland Clinic's Professional Fighters' Brain Health Study

TC: How did you recruit participants for your study?

CB: Well we did it several ways. One was just to beat the bushes. We went to promoters. We went to our Nevada Athletic Commission that regulates the sports. We went to gyms. Surprisingly, we got a very good response. The whole fight industry was very supportive of this project right from the start. And I think that's why it's been successful.

We have now over 750 fighters in the study that we're following. We have men. We have women. We have retired fighters. We have active fighters. And I think the key for us is we know chronic traumatic encephalopathy likely starts many, many years before you have any symptoms. And it's capturing these individuals as the disease begins - from when they're actively getting exposed to head trauma to when they've finished fighting and move on with their lives. So we're in a position, by following individuals actively fighting throughout their career, to get a better sense of how these diseases evolve and how we can detect them early.

We're in a position, by following individuals actively fighting throughout their career, to get a better sense of how these diseases evolve and how we can detect them early.- Dr. Charles Bernick, Cleveland Clinic's Professional Fighters' Brain Health Study

TC: And you're using a variety of methodologies, right, in order to get a sense of what is happening in their brains?

CB: Absolutely, we're trying to be as comprehensive as we can, so we have questionnaires regarding behavior. We try to get a sense of their sleep patterns. We have speech samples. We draw blood for genetics and to obtain chemicals that might be informative in the brain. We have imaging of the brain.

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TC: Can you give me some indication of what you found so far?

CB: Yes there's a couple of things that have popped up somewhat early in this study that's so far, been going on for six years. So for one, we can find from imaging the brain, certain markers that can predict who's likely to have impairment in their cognitive function, in their reaction time.

The other recent finding was that there seems to be certain chemicals in the blood that are released from the injured brain that we can detect that correlate with the amount of exposure a person has had in the recent past. Now these results need to be confirmed with other groups exposed to head trauma in other sports, but if it pans out, it may give us a way to monitor somebody's brain health through blood tests.

Paper in the journal American Journal of Epidemiology, "Professional Fighters Brain Health Study: Rationale and Methods"