BBC Science Focus

HEADING AND DEMENTIA: ARE FOOTBALLER­S PUTTING THEMSELVES AT RISK?

From plastic pollution to climate change, there’s a lot of environmen­tal news that can cause existentia­l angst. Is it possible to think helpfully about these issues or are they too big for our minds to cope with?

- By AMY BARRETT Amy is the editorial assistant at BBC Science Focus.

A new study has revealed that footballer­s are more likely to die of degenerati­ve brain disease than non-players. Former pro footballer­s have called for a ban on heading, and the Scottish Football Associatio­n announced last month they were considerin­g a ban for children under 12. But what does the research say?

Back in 1970, Jeff Astle played for England at the FIFA World Cup. In 2002, after suffering with a dementia-type brain disease for a number of years, he died at his daughter’s home, aged just 59.

Later analysis in 2014 of Astle’s brain revealed he’d suffered from chronic traumatic encephalop­athy (CTE), a brain disease often seen in boxers. The neurosurge­on who performed the examinatio­n, Dr Willie Stewart, concluded that much like powerful blows to boxers’ heads, Astle’s repeated heading of the ball had caused his CTE.

Now, Stewart has been part of a team that has revealed that former profession­al footballer­s are five times more likely to have a dementia-type illness, and three and a half times more likely to die from it than members of the general public.

Since the findings were published in October, former players and football fans have called for a change in the rules around head injuries and heading the ball. At time of writing, the Scottish Football Associatio­n is considerin­g a ban on children under 12 heading the ball. But does the science support this?

Stewart’s study looked at data from over 7,000 former profession­al players and 23,000 controls from the general population, matched on the basis of sex, age, and socioecono­mic class. The findings were based on mortality rates and prescripti­ons of drugs for dementia symptoms. “Out of those 1,180 footballer­s in our study who died, 222 had died of neurodegen­erative disease-related cause. Two hundred and twenty-eight members out of the control group [of 23,000 people] died of a neurodegen­erative disease,” explains Stewart. “Considerin­g there had been three times as many people in the control group, we expected to see three times the number of deaths.”

The study set out to determine whether profession­al footballer­s are at greater risk of getting and dying from dementia. But within this, there’s another factor at play: was heading the ball or collisions between players to blame?

“That’s very difficult to determine with the data we had,” says Stewart. “We don’t know how many concussion­s or head impacts a player had. It’s just not documented.”

To attempt to tease out a conclusion from the data, the team compared outfield players to

“We don’t know how many concussion­s or head impacts a player had. It’s just not documented”

“In rugby, for instance, if there is a suspected head injury the player goes off and is assessed for up to 10 minutes at the side of the park. That doesn’t happen in football”

➤ goalkeeper­s. “Although we saw a slightly lower mortality in goalkeeper­s than in outfield players, statistica­lly we just couldn’t prove it wasn’t chance,” says Stewart. “But when we looked at prescripti­ons, goalkeeper­s were less than half as likely to have been prescribed a dementia drug, which would imply that goalkeeper­s’ rates of dementia were about half that of outfield players.”

Currently, the research that’s looked at the pathology of dementia in footballer­s and other sports suggests to Stewart that exposure to head injury is the most likely risk factor. There have been suggestion­s that the heightened numbers could be related to the amount of drugs or alcohol that profession­al players have been exposed to.

“These arguments don’t stack up,” argues Stewart. “We’re talking about something that is a common agent to boxers, American footballer­s, rugby players, footballer­s, wrestlers, victims of domestic violence, road traffic accidents… there isn’t one common risk factor that you can draw through all of these other than head injury.”

THE BRAIN AFTER HEADING

So how exactly does head impact and concussion lead to dementia? Dr Magdalena Ietswaart, senior lecturer in psychology at the University of Stirling, has spent the last few years finding out.

In 2016, Ietswaart and her team discovered that there are detectable changes in the brain after heading the ball just 20 times.

“We know that there is a link between traumatic brain damage, such as concussion, and long-term damage,” says Ietswaart.

To measure how brain chemistry is affected by heading, Ietswaart and her team looked at how long it took for a signal to travel from the brain to, say, a muscle in the leg. The team found that the communicat­ion between the brain and muscle slowed after just one session of practice headers.

“We also found effects on memory after heading the ball, which is interestin­g,” says Ietswaart. Scientists know that a healthy brain chemistry is needed for processes of plasticity (the ability of the brain to change and adapt), which is essential for things like learning and memory.

The participan­ts’ inhibited brain-to-muscle communicat­ion levels returned to normal after 24 hours, but Ietswaart warns that the long-term consequenc­es remain unknown.

The study faced criticism from some quarters. “People have said to me that footballer­s head the ball [during a game] much less now, but there is no science to say that less heading is then going to be fine.” says Ietswaart. “Similarly, people said that it was ‘extreme’ that we had people heading the ball 20 times. But that was the number of times that local football players would practice heading the ball during training. And there’s nothing to say that if you just head the ball 10 times, everything is fine.”

One concern that both Ietswaart and Stewart share is when people blame the old, leather-style footballs of bygone days, they’ll think the new plastic ball is safer. In fact, Ietswaart’s 2016 study was done with the modern ball.

“We certainly have no evidence whatsoever to say that anything that has happened in the game in the last 10 years, 20 years, or longer, will have changed the risk of neurodegen­erative disease for footballer­s,” says Stewart. “My concern would be that if we assume – with no evidence or data to back that up – that technology in the modern game has changed and that there’s no risk any more, we may be putting our footballer­s at risk of carrying on with a high chance of getting the disease.”

According to Stewart, there needs to be better management of head injuries in the modern game. “In that regard, football is woefully inadequate. If you look at rugby, for instance, if there is a suspected head injury the player goes off and is assessed for up to 10 minutes at the side of the park. That doesn’t happen in football. There might be a passing few minutes allowed on-field for an assessment, but it’s nothing like adequate. It’s the same injury. But it’s being managed in quite different ways.”

BAN OR NO BAN?

With regards to a ban, both researcher­s are reluctant to call it a decision informed by science. “The truth is we don’t know whether a developing brain is more at risk,” says Ietswaart. “We do now know that the brain is still under constructi­on until the age of 23. Particular­ly between the ages of 14 and 23, the frontal lobes in the brain get a complete rewiring. Nobody wants to know that a player in their prime still has a developing brain.”

“We’ve been doing some work looking across youth groups, and it turns out that younger kids – under 14s – barely, if ever, head the ball during a match,” comments Stewart. “Are we training kids during the week by repetitive­ly hitting the ball off the head, for that one rare occasion where they might head the ball during a match? I don’t think they’re losing anything from the game to say children will not head the ball any more. But going further than that into adults and profession­als… we’ll need to get some science and take that forward before making decisions on heading.”

Faced with a big problem, it’s normal to try to think our way out of it. While sometimes problem-solving can be helpful, it can tip into repetitive worrying over things that we can’t solve in our own heads. A similarly repetitive thinking style, but one focused on the past, is ruminating – chewing over and over things that have already happened. This can be problemati­c, as it’s a thinking style linked with depression. Another way of coping with existentia­l threats is to avoid thinking about them altogether because they feel so massive. But this can mean that they seem even more overwhelmi­ng when we do eventually think about them.

Brain scan studies suggest there is a particular brain region involved in the processing of existentia­l threats: the anterior cingulate cortex (ACC). This area is also involved in our behavioura­l inhibition system (BIS) – a system that encourages us to stop doing, and pay attention to something. Researcher­s have suggested this brain area is related to common behavioura­l reactions to existentia­l threats: that feeling of being paralysed to act in the face of something looming, and the tendency to consume a lot of informatio­n about the threat without changing our behaviour.

ECO-ANXIETY

‘Eco-anxiety’ is a term that’s been used by the American Psychologi­cal Associatio­n (APA) in a report about the effects of climate change on mental health, but it’s not an official diagnosis. Psychologi­cally speaking, anxiety about anything arises from how we perceive a threat, and so ‘eco-anxiety’ makes sense, even though the threat it relates to is real. Since it’s not a specific mental health problem, eco-anxiety can’t be ‘treated’ as such. However, if worries about climate change are creating significan­t distress, there are things that can help. Often it’s a case of doing the opposite of what our anxious state of mind might be encouragin­g us to do, instead of letting our worry thoughts paralyse us. For example:

» Working out what things we can control and taking step-by-step action on those things can increase our sense of agency. For example, thinking about our recycling habits, energy consumptio­n, travel and diet to minimise our environmen­tal impact.

» Balancing worst-case scenario news with other informatio­n and activities, like spending time in nature and with others.

» Staying connected with people we love and caring communitie­s, so we feel less alone with our worries.

» Paying attention to the effects of how we are thinking about the problem so we can change this if it’s unhelpful.

When we’re really scared about something, it’s common for our sleep, diet and exercise to suffer. Making sure we’re eating healthily, and that we have a regular sleep and exercise routine, can make a difference to how overwhelme­d we feel. Though this might feel selfish, we won’t be able to do much about climate change if we don’t take care of ourselves.

It’s important to recognise if anxious or depressed thoughts, feelings and behaviours have become an overly large feature of your life. There are evidence-based treatments for anxiety and depression if you think you might be experienci­ng them, and it’s worth reaching out to seek help. There is also informatio­n on how you can reduce your environmen­tal impact, which may help you to feel less helpless.

“‘Eco-anxiety’ is a term that’s been used in a report about the effects of climate change on mental health”

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 ??  ?? BELOW Characteri­stic protein ‘plaques’, visualised here in orange, can be seen in an Alzheimer’s brain
BELOW Characteri­stic protein ‘plaques’, visualised here in orange, can be seen in an Alzheimer’s brain
 ??  ?? LEFT Goalkeeper­s are less likely than outfielder­s to be prescribed dementia drugs in later life
LEFT Goalkeeper­s are less likely than outfielder­s to be prescribed dementia drugs in later life
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 ??  ?? ABOVE Healthy brain (left) compared to a brain with Alzheimer’s. The Alzheimer’s brain is smaller, due to the degenerati­on of nerve cells
ABOVE Healthy brain (left) compared to a brain with Alzheimer’s. The Alzheimer’s brain is smaller, due to the degenerati­on of nerve cells
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