Heading for trouble?

A new study has linked the amount of ball heading in soccer with incidence of neurodegenerative diseases.

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A new UK study of former professional soccer players has linked frequency of heading the ball and increased risk of cognitive impairment in later years.

Those who headed the ball more than a few times per match and in training were more than three times as likely to experience neurodegenerative symptoms in later years than those who rarely headed the ball.

Now, as Women’s World Cup fever sweeps Australia, a leading expert in soccer-related head injuries has told The Medical Republic that women and girls are even more vulnerable to the effects of heading-related impact.

Prior to this study, several large cohort studies reported higher rates of neurodegenerative disease in former professional players relative to the general population. However, none of the studies considered the amount of heading involved and outcomes couldn’t be definitely linked with heading the ball.

Then in 2021, a study of 60 former professional players attempted to quantify heading the ball and the link with neurodegenerative disease in later life, finding that increased frequency of heading was linked with lower scores in cognitive testing.

This current study, published in JAMA Network Open, is the largest study to date and included over 400 retired male professional soccer players in the UK. The average age was around 64 and they played on average almost 500 games.

Participants were asked to estimate the number of times they headed the ball per training session and per match.

They were then assessed for cognitive impairment using the Telephone Interview for Cognitive Status-modified instrument, as well as the Hopkins Verbal Learning Test, verbal fluency, and independent activities of daily living. They were also asked if they’d been diagnosed with dementia or Alzheimer’s disease.

After adjusting for age, BMI, educational level, smoking, alcohol intake, hearing loss and comorbidities, players reporting 6-15 headings per match had almost three times the odds of cognitive impairment than those reporting 0-5 headings per match.

Those reporting more than 15 headings per match had more than three times the odds of cognitive impairment.

The risk of cognitive impairment was further increased when headers in training were considered, and a diagnosis of dementia or Alzheimer’s disease was also associated with increased numbers of headings in matches and training.

The study also looked at the relationship between concussion and later neurological effects, and found increased odds of cognitive impairment among those who’d experienced soccer-specific concussion involving loss of memory.

The main limitation of the study is dependence on player recall of number of headings from several decades ago. There was also no information on the proportion of high force headers from long balls.

“The findings of this cross-sectional study suggest that repetitively heading the ball is a risk factor for cognitive impairment and self-reported dementias in retired UK soccer players,” concluded the authors.

“Further study is required to identify a safe maximum heading frequency per match and training session to mitigate this risk.”

While studies thus far have focused mainly on men and boys, Dr Kerry Peek of the University of Sydney told The Medical Republic that women and girls are particularly vulnerable.

“We know from research that women and girls have higher concussion rates in football (soccer), basketball, baseball and volleyball than men and boys.

“Women and girls are more likely to be injured from ball-to-head impacts, which is a relatively uncommon injury situation in men. The exact reason for this is unknown but our research has shown that women and girls are less likely to be formally trained in heading technique, with adolescent players who have not received this training being more likely to report a concussion.”

Dr Peek, a physiotherapist and researcher in the prevention of head injuries in football, is part of an expert working group on heading and concussion with Football Australia. The group recently published a review of evidence-based strategies to address the negative effects of heading.

She’s also involved in developing and disseminating a program called HeaderPrep in conjunction with Football NSW, which is designed to condition and prepare players for the skills of heading.

Key to better heading techniques is having trained coaches at all levels of the game, said Dr Peek. As many people with kids playing grass roots soccer would have experienced, however, coaches tend to be parents agreeing to take on the role with varying levels of enthusiasm and often little or no coaching training.

“We want parents to put their hands up; volunteers are the lifeblood of community sport,” said Dr Peek.

“But we cannot then blame them for not knowing how to safely teach highly technical skills like heading. Girls and women have even less exposure to trained coaches than boys and men.

“Football has one of the highest participation rates of any team sport in Australia and yet one of the lowest commitments of government investment. If we want our children to be more active, then we need to invest in facilities, coaching, injury prevention initiatives, particularly for women.

“Hopefully one of the legacies of hosting the FIFA Women’s World Cup in Australia will include more investment in women and girls who play all sport, not just football.”

For GPs, Dr Peek said it is important to keep up to date with the concussion literature, even though they may not see that many each week.

She pointed to the consensus statement on concussion in sport, which has recently been updated and has useful resources, such as the Sport Concussion Office Assessment Tool 6.

“Also know who is in your referral network,” said Dr Peek.

“For example, NSW has three specialist concussion services at Westmead Children’s Hospital, John Hunter Hospital/ Calvary Mater Newcastle and Royal North Shore Hospital. But there are also lots of physios and neuropsychologists who work in this space; know who and where they are and refer if needed.”

JAMA Network Open 2023, online 17 July