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Header duel between Wilfred Ndidi and Dele Alli in English Premier League in May 2021
Photo: Laurence Griffiths/Getty Images
Frequent headers and collisions in football change the blood count in the brain.
According to a study among Norwegian players, the damage could disrupt signaling pathways in the body.
The research results, published in the journal Brain Injury, provide further evidence for the long-standing discussion about the dangers of headers.
The Guardian was the first to report it.
Since last July, the English Premier League has had a cap of ten repeated headers per training session – a rule that some coaches are deliberately flouting.
In contrast to the British and US associations, the German Football Association rules out a header ban in children's teams.
In the past, German sports scientists have also questioned whether headers are really sufficiently proven to be the cause of brain damage.
That could change after the new release.
The research team, led by Stian Bahr Sandmo from the Oslo Center for Sports Injury Research, analyzed blood samples from 89 professional footballers from Norway's top league.
Samples were taken when players accidentally injured their heads, whether in play or training;
but also to control conscious training sessions.
Forty-eight players participated in a program that included repeated head practice and, as a control, intensive training of comparable effort, with no head contact allowed.
The difference was clearly visible in the concentration of microRNA in the blood.
These are molecules that play an important role in gene regulation, i.e. the question of when which genetic information is activated in the body fluids.
Six different types of microRNA were affected by head training, but not by non-head contact training.
Accidental head injuries lowered levels of eight different microRNAs.
The study includes a small number of participants, explained Stian Bahr Sandmo.
However, this could help to understand the potentially dangerous consequences of repeated headbutts.
The results are clear enough to use the level of microRNA in blood samples as a biomarker.
This not only diagnoses brain damage as a result of headers, but also the severity of the injury.
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