New Delhi: Football players are 1.5 times more likely to develop neurodegenerative disease than others in their age group, says an observational study published in the medical journal Lancet.

According to the Swedish study that covered 6,007 male football players who played in the Swedish top division between 1924 to 2019, goalkeepers don’t have the same increased risk of neurodegenerative disease as outfield players.

Experts suggest repetitive mild head trauma sustained through heading the ball could be the reason for football players are at increased risk.

The study found that football players had a 1.6 increased risk of Alzheimer’s disease and other dementias as 8% (491 out of 6,007) of footballers covered in the study were diagnosed with the condition compared with 5% (2,889 out of 56,168) of age and sex-matched general population controls.

The researchers found that elite football players had an increased risk of developing Alzheimer’s and other dementias, but their risk was not increased for motor neuron disease including ALS, and their risk of Parkinson’s disease was lower compared to controls.

Unlike outfield players, goalkeepers did not have an increased risk of dementia – suggesting that mild head impacts sustained when heading the ball could explain the increased risk in outfield players.

“Among male footballers playing in the Swedish top division, 9% (537 out of 6,007) were diagnosed with neurodegenerative disease, compared to 6% (3,485 out of 56,168) population controls,” it said.A previous study from Scotland suggested that footballers were 3.5 times more likely to develop neurodegenerative disease. Following this evidence, certain footballing associations implemented measures to reduce heading in younger age groups and training settings.

Authors of the latest Swedish study noted that “although 9% of football players and 6% of controls were diagnosed with neurodegenerative disease, most participants were still alive at the end of data collection, so the lifetime risk of developing neurodegenerative disease for both groups are likely to be higher”.

Outfield players had a 1.4 times higher risk of neurodegenerative disease compared to goalkeepers, the study said.

“Goalkeepers rarely head the ball, unlike outfield players, but are exposed to similar environments and lifestyles during their football careers and perhaps also after retirement,” said Peter Ueda, assistant professor at Karolinska Institutet, Sweden. “It has been hypothesised that repetitive mild head trauma sustained through heading the ball is the reason football players are at increased risk, and it could be that the difference in neurodegenerative disease risk between these two types of players supports this theory.”

The study also found that overall mortality was lower in footballers than the general population, likely because they maintain good physical fitness.