"We found there was in fact increased inhibition in the brain immediately after heading"
Direct changes to brain function after heading a football have been discovered for the first time.
Research by the University of Stirling found "small but significant change" in players who headed a ball 20 times.
The research was led by Dr Magdalena Ietswaart and she explained the methodology.
"In light of growing concern about the effects of contact sport on brain health, we wanted to see if our brain reacts instantly to heading a football. Using a drill most amateur and professional teams would be familiar with, we found there was in fact increased inhibition in the brain immediately after heading and that performance on memory tests was reduced significantly," she said.
"Although the changes were temporary, we believe they are significant to brain health, particularly if they happen over and over again as they do in football heading. With large numbers of people around the world participating in this sport, it is important that they are aware of what is happening inside the brain and the lasting effect this may have."
The risks of heading footballs have been raised before with the case of former England and West Brom footballer Jeff Astle.
He passed away at the age of 59 in January 2002. A prolific header of the ball during his career in the 1970s, when the balls were heavier, a coroner ruled that the former England international's death was a result of a degenerative brain disease caused by minor traumas linked to heading footballs.
In March 2015, his daughter Dawn spoke to Newstalk about the coroner's verdict.
"His verdict was industrial disease. In other words, Dad's job had killed him. This is a landmark ruling and we were absolutely distraught," she said.
"Back in 1998, when he was only 55, we noticed that he was forgetting things. He couldn't remember my son's name after he was born and he asked a few times if his Mum was still alive. My Grandma had died 25 odd years before and we didn't really understand what was happening to him."
Dawn had also added that, "He was so poorly. He could hardly walk. He was only 59 but he looked 159 and he basically choked to death in front of us and we realise now that his brain was so damaged."