LONDON, July 12 (Reuters) - Retired British professional soccer players showed structural brain differences and high rates of anxiety and depression but no signs of cognitive decline in a study looking to establish if repetitive impacts like heading the ball affect the risk of developing dementia.
The study, by researchers at Imperial College London, included 142 former players aged between 30 and 60 and compared them to 56 similarly aged healthy people with no history of contact sports, military service, or past concussions.
In addition to using questionnaires and tests to measure cognition, researchers analyzed structural MRI brain scans from a qualifying subset of 124 players and 40 people in the control group to check for regional differences in grey matter volume.
The authors, who presented the study at the Alzheimer's Association International Conference on Sunday, said their research is part of a major push by scientists to treat repetitive head impacts as a potential modifiable risk factor for dementia in late life, similar to how doctors treat high blood pressure or cholesterol.
It lays the groundwork for what is intended to be a long-term study of these players, whom researchers plan to monitor every two years.
"The field is taking a more holistic view of brain health and dementia risk," said senior author Thomas Parker, a consultant neurologist at Imperial College London.
SIMILAR SCORES ON MEMORY AND THINKING TESTS
After adjusting for factors like age and education, the former players scored as well as expected on memory and thinking tests, showing no significant differences compared to the healthy control group.
Athletes reported much higher rates of mental health struggles, with 31% meeting the threshold for clinical depression compared to 9% of the control group, and 42% reporting clinical anxiety compared to 25%.
Researchers found that the brain scans of the former players showed that, as a group, they had less brain tissue in areas controlling memory and emotion than the control group.
But only 2% of the former athletes showed individual signs of severe brain shrinkage that would point to active, progressive neurodegeneration.
The study has not been peer-reviewed. Researchers expect to submit a paper with a larger sample size and additional analyses of the study later this year.
NO LINK TO ALZHEIMER'S FOUND
The study did not prove a direct link to Alzheimer's disease, a progressive brain disorder that gradually destroys memory and is the most common cause of dementia.
Most research into sports-related brain damage has relied on post-mortem reports and retrospective medical records to study chronic traumatic encephalopathy, or CTE, a degenerative disease linked to repeated head trauma, such as soccer heading or concussions, that can currently only be diagnosed after death.
The Imperial College research follows athletes in mid-life, helping researchers track neurological changes years before dementia would typically be expected to develop.
The results mirror the team's previous peer-reviewed findings from 2025 in 200 retired rugby players, which showed similar grey matter reductions and elevated anxiety, but normal cognitive performance.
Researchers cautioned that their findings cannot predict individual dementia risk.
"We're at a very early stage of translating these findings to individual risk prediction," Parker said.
(Reporting by Bhanvi Satija; Editing by Caroline Humer and Deepa Babington)
