Red Light Therapy May Shield Football Players' Brains

But an unorthodox treatment called red light therapy, which shines powerful near-infrared light at the brain through the skull, may be able to prevent or reduce subtle damage to the brain before symptoms start, by reducing brain inflammation caused by repetitive impacts. A preliminary study with 26 collegiate football players suggests that the therapy could significantly protect players' brains from inflammation over the course of a football season.

The results are published in Journal of Neurotrauma.

The results from the study suggest that red light therapy could protect against brain inflammation. Football players involved in the study received either red light therapy, delivered by a light-emitting headset and a device that clips in the nose, or a placebo treatment with an identical device that did not produce light. Players self-administered the therapy three times a week for 20 minutes a session, throughout the entire 16-week season.

For players on the placebo treatment, brain inflammation increased over the course of the season. Specifically, magnetic resonance imaging (MRI) scans taken at the end of the season showed significantly more signs of inflammation than scans taken at the start of the season. But for players who used the device with an active red light, brain inflammation didn't increase over the season.

"My first reaction was, 'There's no way this can be real,'" says Hannah Lindsey, PhD, research associate in neurology at University of Utah Health and first author on the study. "That's how striking it was." The group receiving red light therapy appeared to be protected from inflammation throughout almost all regions of the brain.

Use of red light therapy for brain health is still in its infancy, but the researchers emphasize that every new therapy starts somewhere, and the potential mechanism of action makes sense. Sufficiently powerful red light can make it through the skull and into the outer surface of the brain, although the amount of light that reaches the brain is a very small fraction of the total. And some previous studies using human cells and animal models have shown that specific wavelengths of light can reduce the levels of some of the molecules that drive inflammation.

The researchers say that while red light therapy is still an emerging technology and more data is needed, they are becoming more convinced of its promise over the course of multiple preliminary studies with people who have experienced head impacts. "When we first started this project, I was extremely skeptical," says Elisabeth Wilde, PhD, professor of neurology at U of U Health and the senior author on the study. "But we've seen consistent results across multiple of our studies, so it's starting to be quite compelling."

An important caveat to the study is its small sample size, which led-due to random chance-to different initial levels of inflammation in the treatment and control groups. This emphasizes that future large randomized clinical trials will be crucial to back up the results in broader populations. The research group is currently starting a Department of Defense-funded randomized controlled trial that will involve 300 people who have persistent symptoms from TBI or concussion, focused on first responders, veterans, and active duty service members. The team is expecting to start recruitment in February or March 2026.

Carrie Esopenko, PhD, associate professor of neurology at U of U Health and second author on the study, hopes that the results will help keep athletes healthy across all sports and age ranges. "We've been trying to figure out how to make sports safer, so that our kids, friends, and family can participate in sports safely for the long term while they're involved in activities that give them happiness and joy," she says. "And this really feels like part of the hope for protecting the brain that we've been searching for."