A recent study by researchers at Boston University reportedly found those who started playing tackle football before the age of 12 developed "more behavioral and cognitive problems later in life" than those who began playing it later.
Ken Belson of the New York Times reported the news Tuesday, noting the study was published in the journal Nature's Translational Psychiatry. Researchers used phone interviews and online surveys with a sample of 214 former players (68 who played in the NFL, 103 who played through college and 43 who played through high school).
Those who started before they were 12 experienced a "twofold 'risk of problems with behavioral regulation, apathy and executive function' and a threefold risk of 'clinically elevated depression scores.'"
One of the study's authors, Robert Stern, addressed an issue with playing tackle football at a young age, per Belson: "The brain is going through this incredible time of growth between the years of 10 and 12, and if you subject that developing brain to repetitive head impacts, it may cause problems later in life."
Belson noted the NFL has recently promoted flag football, and participation from boys between the ages of six to 12 in the tackle version of the sport has dropped by nearly 20 percent since 2009.
This comes after Joe Ward, Josh Williams and Sam Manchester of the New York Times reported in July about a study from Boston University in which researchers found chronic traumatic encephalopathy (CTE) in the brains of 110 of 111 former NFL players who had died.
Mark Fainaru-Wada and Steve Fainaru of ESPN.com reported in August the NFL was conducting its own research on CTE and brain injuries after its partnership with the National Institutes of Health dissolved.