More than 70 former NFL athletes have been diagnosed with a neurological disease postmortem. Researchers can't deny the link between degenerative brain diseases and repetitive head trauma suffered from constant blows out on the field. Some players are taking this information to heart. Back in March, Chris Borland, a top rookie linebacker for the San Francisco 49ers, made the conscious decision to leave the NFL after consulting the research and his family. He weighed the decision, saying to reporters, "From what I've researched and what I've experienced, I don't think it's worth the risk."

Scientists from Boston University Medical Center have added to this growing body of research, but focus their attentions on a crucial window of brain development. The study looks at how early exposure to repetitive head trauma through youth football causes detrimental structural changes in the brain.

The researchers examined 40 former NFL players, who all had more than 12 years of experience playing organized football and at least two years playing for the NFL. Half the participants played tackle football before the age of 12, while the other half began tackle football at 12 or later.

Inga Koerte, a professor of neurobiological research at the University of Munich and one of the study's co-authors, explained how they examined the players:

"… we used an advanced technique called diffusor tensor imaging (DTI), a type of magnetic resonance imaging that specifically looks at the movement of water molecules along white matter tracts, which are the super-highways within the brain for relaying commands and information.”

The researchers found that even though the two groups of players had a similar number of concussions, those who were enrolled in a tackle football team before the age of 12 were more likely to show changes in a part of their brain structure that helps connect the two cerebral hemispheres.

It's thought among researchers that between the ages of 10 to 12, there's a critical window of brain development that could be sensitive to injury during that time. Lead author Julie Stamm, a post-doctoral fellow at the University of Wisconsin School of Medicine and Public Health, explained in a press release that “this development process may be disrupted by repeated head impacts in childhood possibly leading to lasting changes in brain structure.”

However, senior author Martha Shenton of the Harvard Medical School says it's too soon to jump to conclusions.

"The results of this study do not confirm a cause-and-effect relationship; only that there is an association between younger age of first exposure to tackle football and abnormal brain imaging patterns later in life.”

Read more at Science Daily.

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