Former UFC champion BJ Penn has sparked another wave of concern for his wellbeing in the combat sports community by sharing a video on Instagram that casts doubt on chronic traumatic encephalopathy (CTE) as a diagnosis.
The video, featuring Dr. Mark Heisig—a naturopathic physician with degrees from Bastyr University and Northern Arizona University—discusses a March 2024 study examining traumatic encephalopathy syndrome (TES) criteria in the general population.
In the shared clip, Dr. Heisig explains that the study aimed to determine how many “community-dwelling healthy adults” might meet the clinical criteria for TES without having histories of repetitive head impacts. The video suggests that if TES symptoms are common in the general population, the current diagnostic approach may need reconsideration.
“Not all athletes have TES,” the video states. “Maybe it’s not the head impacts, maybe we’ve got to be treating something else.”
A naturopathic physician is nowhere near as qualified as an MD because their education and training are significantly less rigorous. Medical doctors (MDs) undergo four years of medical school, followed by residency programs lasting anywhere from three to seven years, where they treat real patients under the supervision of experienced physicians. In contrast, naturopathic programs are often shorter, less standardized, and lack the depth of evidence-based medical training. Many naturopathic treatments rely on unproven or pseudoscientific methods rather than the rigorous, peer-reviewed science that forms the foundation of modern medicine. Unlike MDs, who must pass rigorous licensing exams and adhere to strict medical guidelines, naturopaths often operate under looser regulations, making their qualifications questionable when it comes to diagnosing and treating serious health conditions.
This post comes amid growing concern from fans about Penn’s recent behavior. Just days earlier, the MMA legend made headlines after claiming on social media that his mother had been replaced by an impostor and accusing a family of murdering his mother and brother—both of whom are reportedly alive.
Many followers expressed worry in the comments section of Penn’s latest post. One wrote, “From a place of love, please seek help,” while another pleaded, “We love you BJ, get help brother.” These comments received numerous likes, indicating widespread concern from fans.
However, some supporters embraced Penn’s skeptical stance, with one commenting, “Great share bro. We all knew this wasn’t adding up,” and another stating, “I’ve been saying this FOR YEARS!!!”
Penn, 45, is widely considered one of the greatest mixed martial artists of all time, having held UFC championships in multiple weight classes during his storied career. His legendary status has made his recent social media activity all the more concerning to longtime fans.
Health experts generally recognize CTE as a degenerative brain condition associated with repeated head trauma, though research continues to evolve regarding its diagnosis and prevalence.
The March 2024 study examining TES criteria in the general population does highlight an important issue—TES symptoms are not exclusive to athletes or those with repetitive head impacts. Research found that a significant portion of community-dwelling adults exhibited symptoms consistent with TES, even without a history of head trauma. This raises concerns about the specificity of TES diagnostic criteria and suggests that other factors may contribute to these symptoms. However, this does not disprove the existence of CTE or its link to head trauma; rather, it underscores the need for careful diagnosis and consideration of differential causes.
BJ Penn’s promotion of this study through a video featuring Dr. Mark Heisig, a naturopathic physician, complicates the discussion. While the study’s findings warrant scrutiny of TES diagnostic criteria, Heisig’s credentials as a naturopath—rather than a neurologist or medical doctor—cast doubt on the depth of his medical expertise in this field.
Penn’s recent social media behavior, including conspiracy-laden claims about his family, has raised further concerns. While his skepticism about CTE may resonate with some, his erratic posts have led many fans to urge him to seek professional help. Given the well-documented links between repetitive head trauma and long-term neurological issues, dismissing CTE outright—especially based on the interpretation of a study by a naturopath—risks oversimplifying a complex medical issue.
