A new study of NFL retirees found that those who began playing tackle football when they were younger than 12 years old increased their risk of developing memory and thinking problems later in life.
The study, published in the medical journal Neurology by researchers at the Boston University School of Medicine, was based on tests given to 42 former NFL players ages 41 to 65 who had experienced cognitive problems for at least six months. Half the players started playing tackle football before age 12 and the other half began at 12 or older.
Those former NFL players who started playing before 12 years old performed “significantly worse” on every test measure after accounting for the total number of years of football played and the age of the players when they took the tests. Those players recalled fewer words from a list they had learned 15 minutes earlier, and their mental flexibility was more diminished than players who began playing tackle football at 12 or older.
While both groups scored below average on many tests, there was a roughly 20 percent difference between the two groups on several measures.
The age of 12 was chosen as a benchmark because it is roughly when brains in young boys are thought to already have undergone key periods of development. Research has shown that boys younger than 12 who injure their brains can take longer to recover and have poor cognition in childhood.
The findings are likely to fuel an already fierce debate about when it is safe to allow children to begin playing tackle football and other contact sports. Youth leagues, some of which allow children as young as 5 to play tackle football, are under scrutiny for putting children at risk from head injuries.
Pop Warner and many other youth leagues have added training protocols, limited contact in practice and adjusted weight and age limits to try to reduce risks from head injuries. But many leagues continue to allow young children as young as 5 to play tackle football.
“Being hit in the head repeatedly through tackle football during a critical time in brain development may be associated with later-life cognitive difficulties,” said Robert Stern, the senior author of the study, who teaches at the Boston University School of Medicine. “The take-home message is: The earlier you start, the more issues you may have.”
