One of the nation’s leading experts on concussions in youth sports, Dr. Robert Cantu, chief of neurosurgery at Emerson Hospital and co-director of Boston University’s Center for the Study of Traumatic Encephalopathy, has teamed up with World Cup champion Brandi Chastain to advocate the end of headers in youth soccer for kids aged 14 and under.
While Cantu acknowledges the science is limited on the connection between soccer with brain injury, he still thinks it’s a smart idea to get heading out of the youth game. The NewsHour’s William Brangham spoke with Dr. Cantu recently for a report about the growing concern over concussions in youth soccer.
This Q&A has been edited for space and clarity.
WILLIAM BRANGHAM: A lot of parents I’ve talked to have said, “We understand the concussion risks with football. But soccer is not football. It’s not hockey. It’s not boxing. This is a relatively safe sport. It’s hugely popular. Kids love playing it, and this is an overwrought concern.” What your response to that?
DR. ROBERT CANTU: Well, they don’t know the statistics. The statistics are that, yes, football has more concussion than does soccer. But soccer kinda falls right behind it. And girls’ soccer is ahead of boys’ soccer.
WILLIAM BRANGHAM: In the number of concussions?
DR. ROBERT CANTU: In the number of concussions that are recognized.
WILLIAM BRANGHAM: More broadly, what do we know about the connection between brain injury and soccer?
DR. ROBERT CANTU: There are a number of studies that show that just from the act of heading the ball, if you do enough of it, there can be structural changes seen. … In this one particular study that’s most cited by a Dr. Lipton in Radiology, it was 885 times a year and higher that they saw these changes.
WILLIAM BRANGHAM: 885 headers per year.
DR. ROBERT CANTU: Headers per year. And if you got up to 1,800 headers, then you started to see cognitive problems in people. There have been retrospective studies that looked at people that played soccer over a long period of time, and have found as compared with people that were not into collision sports, that the soccer players didn’t fare as well.
All of those studies suffer in that they’re retrospective, looking back, and you can always say, “Well, maybe they got their trauma because of lifestyle pursuits or their brain abnormalities because of injury that maybe even happened off the soccer field.”
So, perfect prospective studies are in place. A few of them have been done. And what they have shown is that soccer players’ brains, compared with swimmers, in one case, show greater brain atrophy and abnormality diffusion tensor imaging MRI studies.
So, clearly, there has been structural changes that have been shown as a result of repetitively heading the ball at a very high level of heading. Other studies have shown that there have also been metabolic aberrations, meaning functional MRIs have shown the changes in terms of metabolic activity with individuals that have taken a lot of hits to the head over the course of a given year, even though those hits didn’t result in any recognized concussions. Whether they were unrecognized concussions or not, that’s open to question, but at least none were recognized.
WILLIAM BRANGHAM: You mean, not having a concussion — where you get dizzy, maybe black out a bit. You’re talking about [headers] that might occur a few times in the course of a game, but not feel like they’re causing an injury?
DR. ROBERT CANTU: Absolutely. And in the course of a practice. Hits to the head, accelerations to the head that aren’t immediately joined up with symptoms where you’d be aware that you had a concussion.
In the last year alone, there have been 13 studies that I’m aware of — there might be more– that have shown that sub-concussive hits in sports that take a lotta brain trauma, like soccer in some cases, football in other cases, have shown abnormalities on DTI MRI, have shown abnormalities on functional MRIs … and also breakdown of the blood-brain barrier. … And that’s happened without recognized concussion, just from repetitive trauma. And they found the individuals with the highest degree of abnormalities were those individuals that took the highest number of hits over the course of a season.
WILLIAM BRANGHAM: Is there a difference when we’re talking about the younger brain versus an adult brain? Is this a particular concern when you’re talking about young kids versus older players?
DR. ROBERT CANTU: Yes, I think it’s a huge concern. And there’s a very big difference between the young brain and the adult brain. Some of the key distinctions are that the young brain is largely not myelinated. Myelin is the coating of nerve fibers that connect nerve cells, similar to coating on a telephone wire, it helps transmission but it also gives strength. And so when you violently shake the young brain, you have a much greater chance to disrupt nerve fibers and their connections than you do an adult brain. A young brain is housed in a disproportionately big head. Ninety percent of our head’s circumference has been achieved by the age of five, but our neck strength and size is very small compared to where it will be as an adult.
So, you’ve got a bobblehead doll effect with our youngsters, so that the very minimal impact is now gonna set their brain in much more motion than it would in an adult brain with a strong neck.
Youngsters also, particularly between the ages of 10 and 12, are going through what we refer to as connectivity and pruning of connections of nerve fibers. And the nerve fiber tracks that are going to make up our adult intellect and our adult emotional makeup are largely being fine-tuned during that two-year period. And injuries that occur to the brain during those two-year periods may result in somebody not reaching their maximal intellectual state or the stability emotionally that they otherwise were genetically programmed to reach because of brain injury.
So, youngsters have a number of things going on where their developing brain—that make them not only more prone to injury but slower to recover from injury and have a greater chance for long-lasting effect.
WILLIAM BRANGHAM: So, do these effects go away? If you stopped playing, can you, in effect, heal?
DR. ROBERT CANTU: Well, that’s where I’ve got a great advantage over a researcher working at– in– in a laboratory or working at a tertiary institution. I’ve got 45 years of having followed youngsters playing sports, youngsters having brain injuries. And I’ve seen a number of youngsters. The overwhelming majority completely recover as best I can measure it from most of the concussions that I have seen over the course of my career. Because I see a lot of post-concussion syndrome, though, I’ve seen a lot of youngsters also who’ve had life-altering changes because of brain injuries sustained from repetitive concussions.
WILLIAM BRANGHAM: Life-altering?
DR. ROBERT CANTU: Life-altering. Meaning by that, that although they eventually were able to go further with their education, and in most cases go on to college, they’re no longer the same personality in many cases. And many of them are having to work far harder and achieve results not as successful as they were achieving at a younger age, which– with much less effort.
WILLIAM BRANGHAM: Why is it that some players, some young athletes can have a certain number of headers or concussions and come through it seemingly unscathed, and others don’t? Why is that? Is there some protective mechanism that some people have and others don’t?
DR. ROBERT CANTU: William, that’s the $64,000 question we’re all studying. Why do some people recover– the overwhelming majority recover from concussions and others go on to post-concussion syndrome? And why do a certain group of people subjected to the same degree of head trauma as somebody else go on to have a later-life neurodegenerative disease that we call chronic traumatic encephalopathy?
There’s no question that most of us feel there are genetic factors. And there are probably environmental factors as well. We don’t know the answers to just what they are today. … But there’s no question that somebody– some people seem genetically programmed to develop problems with the same degree of head trauma as somebody else can have that head trauma and not develop those problems.
WILLIAM BRANGHAM: But as a parent, as a coach, as a kid themselves, there’s no way of knowing if you’re that person or not.
DR. ROBERT CANTU: Right now today, there’s no way of knowing. We don’t know what the genetic makeup is that is putting these people at risk. What we do know, though, is something that I think everybody knows intuitively without a researcher or a scientist or a doctor telling them, and that is, to get hit in the head is not a great thing if you can avoid it.
Let’s not get paranoid about it. We’re all gonna hit our heads. We’ve got a marvelous protection system going between the scalp, the skull, the cerebral spinal fluid in the brain inside the water bath.
But if I were to sit here and hit you as hard as I could with a pillow, that’s about what your sustaining with heading soccer balls, especially from close contact. And I’d be charged with child abuse if I whacked my child 20 times with a pillow as hard as I could. And yet, that’s pretty common stuff over the course of a number of soccer games at the youth level.
So, I think we need to look at our sports and examine them and say, “How can we still play them?” Lord knows, I want everybody to be playing sports. I want sports to be played by more people than are playing them now. If we’re not playing sports as a kid, we’re probably not gonna be very active as an adult. And that has huge health consequences as well as emotional issues. So, we need kids playing sports. But I think we need them playing sports safer. And at certain ages, the sport can be altered to make it safer. Take the most injurious activity for head injury out of it, but let the rest of the sport go on. And that’s playing soccer without heading.
It’s playing flag football at the very early ages instead of tackle football. These things can be done and the sports can still be played. And the interesting thing is, when I talk with a Brandi Chastain or I talk with other elite world-class athletes that have played this sport at the highest level, they tell me, now that they’re soccer moms and soccer coaches- they tell me the kids play better soccer at the early ages if they don’t try to head the ball. Take the ball off the chest, the thigh or the leg, because they can control it better than they can with their heads at that age. So, they actually function better. And, of course, they function much more safely.
Because in the act of heading, that’s when accidentally heads collide with other heads, heads collide with other body parts — elbows, shoulder, a wrist– and that’s when concussions happen. So that the risk in heading the ball isn’t just the heading the ball properly. It’s the risk of getting a concussion as well.
WILLIAM BRANGHAM: I know one mom in particular who’s interested in trying to do what are called “baseline evaluations” of players ahead of time. Can you explain what the concept behind that is and why that might be useful?
DR. ROBERT CANTU: Yes. At all levels, baseline evaluation is very, very important. And what you’re really wanting to do is have the baseline evaluation be whatever is going to be the assessment that the individual will have if they’re suspected of having a head injury, if they’re suspected of having a concussion.
And what we do know is there’s no single test that’s uniformly accurate in diagnosing concussion except in the minority of cases where somebody’s unconscious. If somebody’s rendered unconscious, you know they’ve had a concussion. That happens less than 10 percent of the time. The other 90 percent of the time, it’s having one or more of the 26 post-concussion symptoms that we look for.
And here, it’s very important to have baseline balance evaluation, because you’re gonna use balance in evaluating after–
WILLIAM BRANGHAM: Testing their ability to stand upright under certain circumstances.
DR. ROBERT CANTU: Yes. We normally use standing with two feet together, eyes open, eyes closed, one foot, heel toe, in front of the other– so-called “tandem stance,” eyes open, eyes closed. And then single leg stance– eyes open, eyes closed.
WILLIAM BRANGHAM: So, you test them when they have not been injured to get a baseline, and then if they are suspected of having something later, you test them again to see if there’s a difference.
DR. ROBERT CANTU: Yes. And you wanna test them for their baseline at a resting state, not exerted, so it’s optimal conditions. Yes, you want to know whether, when you’re seeing someone and they’re making errors now, “Is this really reflecting a change from their baseline?”
WILLIAM BRANGHAM: –or were they always this way?
DR. ROBERT CANTU: Or were they always that way? And that’s exactly the case.
WILLIAM BRANGHAM: Do you worry that by focusing on the injury-causing potential of kids’ sports you’ll actually scare kids and parents away?
DR. ROBERT CANTU: I want parents to not for a second think about not having their kids play sports. It’s vital that they play sports. Now what sports they play and how they play those sports, we can have a discussion about that perhaps. But definitely kids need to be in sports. And those that are playing contact/collision sports hopefully are gonna be playing them under coaches that are gonna teach the proper technique and under coaches that are gonna minimize the full contact aspects of practice and be teaching skill drills whenever possible.
We can greatly eliminate the chance for concussion and drastically reduce the amount of subconcussive trauma by just reducing the way we practice sports, taking the full collision practices and holding them to a bare minimum.
WILLIAM BRANGHAM: So, since you’re a father — let’s say you were today a father of young kids, would you encourage them to play soccer, wholeheartedly?
DR. ROBERT CANTU: I would wholeheartedly want my children playing soccer. If they were young, if they were under the age of 14, I would ask them to not head the ball and make a little pact with the coach. And that probably would preclude what positions they played on the soccer team somewhat, but I would want them playing soccer full-bore.
WILLIAM BRANGHAM: But you would like leagues around the country to universally say, “We’re gonna take heading out of the game for young kids.”
DR. ROBERT CANTU: Yes, I would. Because it would greatly reduce the head trauma these youngsters are subjected to, number one. And number two– taking the lead from the Brandi Chastains and the Cindy Parlows and the Joy Fawcetts of the soccer world, it would, in their opinion, enhance teaching of soccer skills, the foot skills that are the hallmark of the sport and the awareness skills of where you are on the field — that are equally as important. And they believe that it would not hurt the product by the time one got in– in– high school. If you wanted to work on some heading drills at an earlier age, head with a much lighter ball, a beach ball or a lighter soccer ball.
Watch a report by William Brangham on parents’ concerns over soccer safety.
WILLIAM BRANGHAM: And so your scientific opinion is that once the children get into the late teen years, once they get into high school, that they can then physiologically, safely head the ball in soccer.
DR. ROBERT CANTU: More safely. Yes. We don’t know that if you’re heading it an excessive amount of time, even at the high school level, that there are not some issues to be concerned about. … But it’s certainly much safer than it is at younger ages.
WILLIAM BRANGHAM: Does strengthening the neck help protect the head?
DR. ROBERT CANTU: We’ve had, for years, the belief that neck strength reduces your chance of having a concussion — if you see the hit coming. And it’s based on several practical things. One is in a study of NFL players that were in the open field.
The person that didn’t see the hit coming was concussed every time there was a concussion. The hitter never was. And yet if you take two people, each of whom see the hit coming, you can’t predict who’s gonna have a concussion, if there is a concussion. And it was because the person didn’t see the hit coming, their neck was relaxed.
And then in the last six months there’s been a publication by Cindy Collins and Dawn Comstock that looked at the incidence of concussion compared with neck strength in high school athletes, across sports. And it was found across sports that those with the stronger necks had fewer concussions. Those with the weakest necks had the highest incidence
WILLIAM BRANGHAM: What about helmets? What about the soccer helmets? Do those offer any protection?
DR. ROBERT CANTU: Soccer helmets offer protection from scalp lacerations and scalp hematomas. They don’t offer protection from concussion. Unfortunately, even football helmets do little to– protect against concussion.
And the reason is, that although helmets do a fabulous job preventing and reducing linear forces over a very small focal area, they don’t do much for the rotational forces. And that’s what you wind up with primarily when two heads collide. And when a head with a rigid neck and a big body collides with another head, it’s gonna move it quickly.
And that movement very quickly is what sets up the rotational forces inside the brain that result in a concussion.
WILLIAM BRANGHAM: So, you think soccer could make this adaptation — take heading out of the kid’s game — and the game that so many kids and parents love will not be grievously changed.
DR. ROBERT CANTU: I hope it becomes even more popular. Because if you took heading out of soccer, it wouldn’t be behind football in the incidence of concussion. It wouldn’t even be in the high-risk group. It would be in a low-risk group. It’s not gonna mean that every concussion’s gonna come out of it. No. You can get a concussion in any sport.
But it would no longer be in the high-risk group if you took that one act out of it. And you can still play the sport at the youth level at a higher level if you don’t try the heading.