2 student football players killed, 2 more suffered head injuries in the 1st week of the season. Here’s what the data tells us about the risks of playing the sport.

It has been a tragic and alarming start to the school football season this past week in at least three different states: Alabama, West Virginia and California.

On Friday, high school quarterback Caden Tellier, 16, was tackled in the third quarter during the home opener for John T. Morgan Academy in Selma, Ala. School officials announced Saturday that Tellier died after sustaining a critical brain injury.

In West Virginia, Cohen Craddock, 13, a middle school student, was taken to the hospital Friday after sustaining a head injury during team practice that resulted in brain swelling. Medical officials said he died on Saturday at the hospital.

A Friday-night football game at Coachella Valley High School in California saw two Xavier Prep players sustain serious head injuries. One was airlifted to Moreno Valley hospital, while another was wheeled away on a stretcher. Both Xavier Prep players are expected to recover from their injuries.

Deaths while playing football are a rare occurrence, according to data collected by the National Center for Catastrophic Sport Injury Research. But researchers warn that tackle football and a culmination of hits to the head starting at a young age can significantly increase the risk of long-term cognitive harm.

Here’s a look at some of the data:

Football-related deaths due to head injuries

In 2023, there were 16 deaths during among collegiate, high school, middle school and youth-league football players in the United States, according to the National Center for Catastrophic Sport Injury Research. Of those 16 deaths, three were caused by traumatic brain injuries that occurred during games. In 2022, there were three football-related deaths due to traumatic brain injuries among high school players.

What is a traumatic brain injury (TBI)?

“TBI can be caused by a forceful bump, blow or jolt to the head or body, or from an object entering the brain. Not all blows or jolts to the head result in TBI,” according to the National Institute of Neurological Disorders and Stroke.

There are two types of TBI. One is a closed brain injury, which happens when there is nothing penetrating the skull or brain. It’s usually caused by a rapid forward or backward movement, causing the brain to move within the skull. It “results in bruising and tearing of brain tissue and blood vessels,” according to Johns Hopkins Medicine.

The other is a penetrating brain injury, which happens when the skull is broken, like when a bullet pierces the brain.

The link between football and CTE

A degenerative brain disease called chronic traumatic encephalopathy (CTE) can result from repeated traumatic brain injuries.

A Boston University study on CTE in National Football League players found that about 92% of 376 former NFL players whose brains were studied postmortem had CTE.

The disease has also been associated with other contact and collision sports, like boxing, soccer, ice hockey and rugby. CTE is linked with a wide range of cognitive issues, including memory loss, depression, early-onset dementia and suicidality.

Read more:Will Guardian Caps solve football's concussion problem? The NFL is trying.

While the NFL study made headlines, college and high school players have also been found to have been affected by CTE.

Additional research from Boston University’s School of Medicine has shown that repetitive hits to the head, even if they don't result in concussion, can result in CTE. For every year that a player absorbs repeated head collisions, their risk of developing CTE increases by 30%. For every 2.6 years, the risk of developing CTE doubles, according to Boston University researchers.

So if a child starts playing football at age 5, they have 10 times the odds of developing CTE compared with kids who start playing at age 14.

This data has left many families to weigh the risks and benefits associated with the sport — and weighing alternatives.

The alternatives

“Having a collision sport or a contact sport doesn’t mean that that collision or contact has to involve the head,” said Dr. Allen Sills, chief medical officer of the National Football League, told CNN in 2023. “You can play a sport in which there is contact between or among players, but we should try to get the head out of that contact whenever possible.”

The NFL has recently implemented changes for its 2024-25 season regarding its kickoff rules, while players have the option to wear Guardian Caps in an effort to reduce concussions and minimize head contact. In 2018, the NFL banned players from lowering their heads to make forcible contact with their helmet.

When it comes to collegiate football, the National Collegiate Athletic Association (NCAA) has similar rules in place. The 2023 NCAA rulebook says if a player makes “forcible contact to the head or neck area of a defenseless opponent with the helmet, forearm, hand, fist, elbow or shoulder,” then that player should be penalized.

And youth football leagues have made some changes to reduce the risk of head trauma, like limiting how much practice time can be spent on contact drills. While no state has outright banned youth tackle football, efforts have been made to do so, like when California considered a bill to ban tackle football for kids younger than age 12.

The Centers for Disease Control and Prevention also offers suggestions for minimizing head injuries in football like reducing the number of contact practices, to lower head impacts during football. The agency also offers flag football as an alternative to tackle football at a young age, after a CDC study found that tackle athletes ages 6 to 14 had 15 times more head impacts during a practice or game, compared with flag football players, a low-contact sport.

The CDC study found that youth tackle football players had an average of 378 head impacts per player over the course of one single season, compared with eight head impacts of flag football athletes.

The American Academy of Pediatrics (AAP) addressed concerns from experts that when tackling is introduced at a later age, like 14, those athletes won’t be prepared and will get seriously injured.

“If regulations that call for the delaying of tackling until a certain age are to be made, they must be accompanied by coaches offering instruction in proper tackling technique as well as the teaching of the skills necessary to evade tackles and absorb being tackled,” the AAP said in a policy statement on “Tackling in Youth Football.