Red light therapy is emerging as a potential tool to protect the brain from repeated head impacts, according to new research involving college football players. These findings highlight a possible shift toward prevention, rather than treatment, of long-term brain damage linked to repeated exposure to head acceleration.
Repeated head impacts occur far more often than many people realize. Athletes in contact sports, military personnel, and emergency responders experience frequent jolts to the head and body. Even when no concussion is diagnosed, these forces can place cumulative stress on brain tissue. Over time, this silent strain may contribute to serious neurological problems.
Scientists at the University of Utah are studying whether red light therapy can help protect the brain during periods of ongoing exposure. Their recent study suggests this approach may reduce inflammation and preserve brain structure before symptoms appear.
Why repeated head impacts damage the brain
Decades of medical research link repeated head acceleration to long-term brain disorders. Conditions such as chronic traumatic encephalopathy develop gradually, often without early warning signs. Symptoms may include memory loss, mood changes, confusion, and cognitive decline later in life.
Even impacts that do not directly strike the head can transmit force upward, stressing delicate brain tissue. Inflammation plays a central role in this process. While short-term inflammation helps repair injury, repeated immune activation damages neurons, disrupts communication between brain cells, and weakens natural repair mechanisms.
How red light therapy supports brain health
Red light therapy, also called photobiomodulation, uses red to near-infrared light delivered through the scalp and nasal cavity. The light penetrates outer brain layers and interacts with mitochondria, the structures responsible for cellular energy production.
At a wavelength of 810 nanometers, red light boosts energy availability inside brain cells and improves oxygen use. This added energy helps neurons recover from stress. Red light therapy also reduces harmful inflammatory signals, limits oxidative stress, improves blood flow, and stabilizes calcium levels inside neurons.
These combined effects help protect nerve fibers and support healthy brain communication during repeated strain.
Testing red light therapy in football players
The study followed 26 male collegiate football players aged 18 to 25. Participants were randomly assigned to receive either active red light therapy or a sham treatment. Both groups used identical devices, but only the active group received near-infrared light.
Players completed 20-minute sessions three times a week throughout a 16-week football season. Researchers conducted brain scans before and after the season using advanced magnetic resonance imaging techniques.
The scans measured immune-related inflammation and the organization of white matter fibers, which are essential for efficient brain signaling.
What the brain scans revealed
Players in the sham group showed increased markers of inflammation and axonal stress as the season progressed. Imaging data revealed signs of immune cell buildup and strain on white matter structures.
In contrast, players who received red light therapy showed far greater stability across multiple brain regions. In some areas, inflammation markers decreased over time. These findings suggest reduced immune activation and better preservation of brain structure.
Researchers described the results as striking, noting the consistency of protection seen across vulnerable regions of the brain.
Protecting high-risk brain regions
Repeated head acceleration tends to affect specific areas, including the brainstem, midbrain, corpus callosum, and deep white matter tracts. Mechanical forces concentrate in these regions, creating what scientists call a cone of vulnerability.
Red light therapy appeared to limit inflammation in many of these high-risk zones. Some protective effects extended beyond the most stressed regions, indicating broader benefits to overall brain health.
A shift toward prevention
Senior author Dr. Elisabeth Wilde, a neurologist at the University of Utah, noted that early skepticism has given way to cautious optimism as results have remained consistent across studies.
Larger trials are now planned, including a Department of Defense–funded study involving military personnel and first responders. If future research confirms these findings, red light therapy could offer a noninvasive and drug-free method to protect brain health during repeated exposure.
Rather than waiting for injury to occur, red light therapy may help reduce long-term neurological risks and support healthier outcomes for athletes and others in high-impact professions.
The study was published in the Journal of Neurotrauma.
