For years, the discussion about football and brain injury centered on one question:
“How many concussions did you have?”
But a major 2026 study published in The BMJ and today reported in the New York Times, suggests we need to think bigger.
The real concern may be the cumulative effect of repetitive head impacts over a lifetime.
Researchers studying deceased former NFL players found striking evidence of chronic traumatic encephalopathy (CTE), a progressive neurodegenerative disease associated with repetitive head trauma.
At Least One in Four Had Confirmed CTE
Between 2016 and 2021, 878 former NFL players died. Among the 235 players whose brains were donated and examined, 215—or 91.4%—had CTE.
That number requires perspective. Families concerned about a former player’s neurological symptoms may be more likely to donate the brain for research, creating potential selection bias.
Researchers therefore calculated an extremely conservative estimate by assuming that every player whose brain wasn’t donated did not have CTE.
Even under that assumption, 215 confirmed cases among 878 deceased players produces a prevalence of approximately 24.5%—almost one in four.
That’s a remarkable finding.
It’s Not Just About Concussions
CTE isn’t simply about diagnosed concussions.
Increasing attention is being directed toward repetitive head impacts, including impacts that may never produce obvious concussion symptoms.
A football player can experience hundreds or thousands of these impacts over years of practices and games.
The spectacular collision that makes the highlight reel gets everyone’s attention. The repetitive hits that don’t make the highlight reel may ultimately be just as important.
What Happens Inside the Brain After Trauma?
An important review by neurosurgeon Dr. Joseph Maroon and colleagues, published in The Physician and Sportsmedicine, helps explain what may happen after the initial trauma.
Maroon and his colleagues examined the pathophysiology of post-concussion syndrome and emphasized that a concussion isn’t necessarily over when the headache disappears.
Following brain trauma, a complicated biochemical cascade can occur involving inflammation, excitatory neurotransmitters, oxidative stress, and altered neuronal function.
The authors discuss immunoexcitotoxicity—the interaction between inflammatory processes and excessive neuronal excitation—as a possible contributor to persistent post-concussion symptoms.
The initial impact may occur in a fraction of a second.
The biological response to that impact can continue long afterward.
That raises an important question: beyond preventing unnecessary head impacts, can we do more to support the health of the brain before and after trauma?
CTE and Dementia
The 2026 BMJ study also reported a concerning relationship between CTE severity and cognitive decline.
Among NFL brain donors with CTE, 61.3% met clinical criteria for dementia. More severe CTE pathology was associated with dementia and greater impairment in cognition and activities of daily living.
That doesn’t mean everyone with CTE will develop dementia. But it underscores why prevention deserves serious attention.
What Can We Do to Protect the Brain?
The first line of defense is reducing unnecessary head impacts.
That means better tackling techniques, limiting repetitive contact during practice, recognizing concussion symptoms, avoiding premature return to play, and giving the brain adequate time to recover.
But the biochemical processes discussed by Maroon and colleagues also make nutrition and metabolic health fascinating areas of research.
If I were participating in a sport involving repetitive head trauma, maintaining adequate nutritional status—including magnesium, omega-3 fatty acids, vitamin D and vitamin K—would certainly be part of my personal preventive health strategy.
Magnesium and the Calcium Problem
Magnesium deserves particular attention because it plays an important role in NMDA receptor activity, neuronal excitability, and calcium regulation.
After brain trauma, excessive excitatory activity can contribute to abnormal calcium movement into neurons. Excessive intracellular calcium is one component of the secondary biochemical cascade associated with cellular dysfunction and neuronal injury.
Magnesium acts as an important physiological regulator of NMDA receptor activity and calcium entry.
This makes forms of magnesium capable of increasing magnesium availability within the nervous system particularly interesting.
Magnesium L-threonate has been studied for its ability to increase brain magnesium in experimental research and for potential effects on synaptic function and cognition.
Magnesium taurate combines magnesium with taurine, another compound involved in neuronal signaling and calcium regulation.
The biological rationale is compelling, and if I were playing a repetitive-impact sport, magnesium L-threonate or magnesium taurate would be something I would be taking 300mg of each of these magnesium types for an athlete around 200lbs.
Omega-3 Fatty Acids: Building Blocks for the Brain
The case for omega-3 fatty acids—particularly DHA and EPA—becomes even more interesting when we look specifically at traumatic brain injury research.
Maroon and colleagues discussed omega-3 fatty acids as a potential nutritional approach to post-concussion syndrome. An extensive review published in the Journal of Neurotrauma went even deeper.
In “Omega-3 Fatty Acids as a Putative Treatment for Traumatic Brain Injury,” Hasadsri and colleagues reviewed the scientific literature surrounding TBI, neuronal injury, and omega-3 fatty acids.
The authors described DHA and EPA as having some of the most promising laboratory evidence among nutritional compounds being investigated for potential neurorestorative effects following TBI.
Why might omega-3s matter?
DHA is literally an important structural component of the brain.
It is highly concentrated in neuronal cell membranes and plays important roles in normal membrane function and neuronal signaling.
Following traumatic brain injury, the initial mechanical event can be followed by a secondary cascade involving inflammation, oxidative stress, disruption of neuronal membranes, altered cellular signaling, and impaired neuronal function.
Experimental research reviewed by Hasadsri and colleagues reported potential effects involving neuronal cell survival, membrane homeostasis, neuroplasticity, oxidative damage, cognition, and functional recovery following brain trauma.
One particularly interesting area involves brain-derived neurotrophic factor, or BDNF, which plays an important role in neuronal survival, synaptic plasticity, learning, and memory. Experimental TBI research found that dietary omega-3 fatty acids could help normalize BDNF, reduce oxidative damage, and improve learning following brain trauma.
There is the initial mechanical injury—and then there is the biochemical response that follows it.
If repetitive head trauma repeatedly challenges neuronal membranes, inflammatory pathways, oxidative balance, and cellular repair mechanisms, it makes sense to investigate whether nutritional status before and after those impacts could influence resilience and recovery.
The human evidence is still developing, so we cannot say that fish oil prevents concussion or CTE. But we also shouldn’t ignore biological and experimental evidence suggesting that DHA and EPA may support many of the neuronal processes challenged by brain trauma.
If I were regularly exposing my brain to repetitive impacts through football, hockey, soccer, or another contact sport, maintaining adequate DHA and EPA levels would certainly be part of my personal nutritional strategy. The maintenance dose is considered to be 3g of highly purified omega-s’s. If my brain was at risk due to a sport, I would bump it up to 7 grams or a tablespoon per day.
Don’t wait until after the brain is injured to start thinking about brain health.
Vitamin D: An Important Clue From NFL Players
Vitamin D becomes especially interesting because Maroon and colleagues didn’t just theorize about its importance—they studied it in professional NFL players.
In a 2015 study published in The American Journal of Sports Medicine, researchers measured serum vitamin D in 80 professional football players.
The average vitamin D level was 27.4 ng/mL. Way too low!
Players released during the preseason because of injury or poor performance had significantly lower vitamin D levels than players who went on to play during the regular season.
The authors concluded that professional football players with higher vitamin D levels were more likely to obtain an NFL contract position and that vitamin D-deficient players might be at greater risk for bone fractures.
Even elite NFL athletes can have inadequate vitamin D levels—and nutritional status may be associated with meaningful aspects of an athlete’s health and performance.
That’s why I don’t think the conversation about protecting contact-sport athletes should begin after the concussion.
It should begin before the first hit.
Vitamin D is involved in calcium and phosphate regulation, musculoskeletal health, and numerous other physiological processes. Vitamin D receptors are also present throughout the nervous system.
For athletes participating in football, soccer, hockey, boxing, or other repetitive-impact sports, knowing your 25-hydroxyvitamin D blood level and addressing deficiency with an appropriate healthcare professional makes sense as part of a broader preventive health strategy.
Vitamin K is also frequently discussed alongside vitamin D because of their complementary roles in calcium metabolism.
If I were playing football or soccer today, maintaining an adequate vitamin D level—along with vitamin K—would be part of my personal health regimen. A minimum dose would be 5,000 IU with vitamin K.
The Boston Connection
Boston has become one of the world’s centers for CTE and repetitive-head-trauma research, making this subject particularly relevant to athletes, parents, coaches, and healthcare professionals throughout Boston and Massachusetts.
And the implications extend far beyond professional football.
Football, hockey, soccer, boxing, military service, and other activities can expose people to repetitive head impacts.
The emerging message is straightforward:
Brain health needs to be considered over a lifetime.
Reducing repetitive impacts remains the priority. But understanding neuronal metabolism, inflammation, excitotoxicity, calcium regulation, neuronal membrane health, and nutritional factors such as magnesium, omega-3 fatty acids, vitamin D, and vitamin K may open additional avenues for supporting long-term brain and overall health.
We cannot currently say these supplements prevent CTE. However, extensive biological research says these supplements have very significant beneficial effects on the brain and you want to do everything in your power to protect yourself and those you love from brain injury and degeneration.
There are legitimate scientific reasons to investigate their roles in maintaining neurological and metabolic health. The Hasadsri review provides an especially compelling rationale for continued investigation of DHA and EPA in traumatic brain injury, while Maroon’s research reminds us that even world-class NFL athletes can have nutritional deficiencies worth addressing.
Considering the potential consequences of repetitive head trauma, protecting the brain before damage accumulates may ultimately prove far more effective than waiting decades to address the consequences.
Where Does Chiropractic Fit Into a Concussion Protocol?
There may also be an important role for evaluation of the cervical spine and cranio-cervical junction as part of a comprehensive concussion protocol.
The concept makes biomechanical sense: an impact capable of rapidly accelerating and decelerating the head and brain also exposes the cervical spine to substantial forces. Persistent symptoms following concussion—including headache, dizziness and neck pain—therefore should not automatically be viewed as originating exclusively within the brain.
An August 2016 summary article published on the ChiroTrust review explores a proposed relationship between the upper cervical spine, cranio-cervical junction, vascular circulation, and cerebrospinal fluid (CSF) dynamics. It discusses the hypothesis that altered cranio-cervical mechanics could, under certain circumstances, influence normal CSF and vascular hydrodynamics. ChiroTrust article.
In the article, the case of former Chicago Bears quarterback, Jim McMahon was reviewed. McMahon received chiropractic care on this upper neck and had a remarkable recovery from his concussion symptoms. This article raises a very reasonable clinical question:
We evaluate the brain after a traumatic impact while ignoring the cervical spine that experienced the same traumatic event?
For patients experiencing persistent post-traumatic headaches, neck pain, dizziness, balance disturbances, or cervical dysfunction, a careful cervical and cranio-cervical evaluation may deserve a place within a multidisciplinary concussion protocol. When appropriate, chiropractic care may have a role in addressing identified cervical musculoskeletal dysfunction while neurological and medical aspects of the concussion continue to be appropriately managed.
The bigger message is simple: concussion care shouldn’t necessarily stop at the brain. The brain, cervical spine, and cranio-cervical junction function as an interconnected system—and after trauma, it makes sense to evaluate the entire system.
Literature Citations
Maroon JC, LePere DB, Blaylock RL, Bost JW. Post concussion syndrome: a review of pathophysiology and potential nonpharmacological approaches to treatment. Physician and Sportsmedicine. 2012;40(4):73-87. doi:10.3810/psm.2012.11.1990.
Hasadsri L, Wang BH, Lee JV, Erdman JW, Llano DA, Barbey AK, Wszalek T, Sharrock MF, Wang H. Omega-3 Fatty Acids as a Putative Treatment for Traumatic Brain Injury. Journal of Neurotrauma. 2013;30(11):897-906. doi:10.1089/neu.2012.2672.
Maroon JC, Mathyssek CM, Bost JW, Amos A, Winkelman R, Yates AP, Duca MA, Norwig JA. Vitamin D Profile in National Football League Players. American Journal of Sports Medicine. 2015;43(5):1241-1245. doi:10.1177/0363546514567297.
ChiroTrust. A Plausible Link Between the Brain, the Cervical Spine, and Cerebral Spinal Fluid Flow. ChiroTrust. Review of research concerning the cranio-cervical junction, cervical trauma, CSF hydrodynamics, vascular flow, and neurological function. ChiroTrust source article
