The cause of his condition was believed to be the cruel intrusion of Parkinson’s, which resulted from three decades of continuous hits to the head. His greatness, however, was largely attributed to his outdoor training and exposure to pesticides, as well as his genetic predisposition. His family does not believe that boxing was the sole cause.
They may be partly right. Although it’s not clear if Ali possessed them, there are genes associated with a higher risk of Parkinson’s. Some studies point to toxins from pesticides targeting the delicate motor nerves in the brain. There is also undeniable evidence that the same neurons can damage the brain from repeated trauma.
It can only be done posthumously for now, as diagnosing CTE is still difficult. Today, scientists have a deeper understanding of how brain trauma may contribute to other brain diseases like Alzheimer’s and Parkinson’s. The connection between boxing in a career and the series of symptoms that include tremors and slurred speech has been known by doctors since the 1920s, which was compelling enough for them to dub it as chronic traumatic encephalopathy (CTE) or the pugilistica dementia syndrome.
According to Dr. Robert Cantu, a neurosurgery professor at Boston University and a prominent researcher on chronic traumatic encephalopathy (CTE), it is widely believed within the field of neurodegenerative diseases that Muhammad Ali developed Parkinson’s disease as a result of experiencing brain injuries throughout his career.
Researchers have found that people who experience repeated head trauma are more likely to develop Parkinson’s, suggesting that there is a significant gap in our understanding of this issue, as noted by Dr. Michael Okun, the medical director for the National Parkinson Foundation. However, it is still premature to definitively assign causation.
There is no single answer that will explain what occupational hazards could contribute to the progression of Parkinson’s in the same way that exposure to pesticide chemicals could accelerate or exacerbate underlying problems and magnify head injuries. Scientists do not fully understand how the buildup of proteins like tau, which is a telltale sign of neurodegenerative diseases such as Alzheimer’s, can trigger brain injuries or how it could potentially accelerate or amplify underlying problems.
The punches from head to toe could have heightened any damage that had already occurred. Both Ali and the case with whom he had fought last may have already been showing signs of Parkinson’s, with uncoordinated movements and slurred speech.
Investigations on brain tissue from individuals such as Ali, who encountered frequent brain injuries and subsequently developed Parkinson’s disease, are crucial for elucidating these inquiries. However, such investigations are currently non-existent. The National Institutes of Health recently initiated a study that retrospectively examines the medical records of individuals who developed Parkinson’s disease, but the extensive duration required for Parkinson’s disease to manifest makes it financially burdensome to track individuals over many years. If a cause-and-effect relationship between head trauma and brain disorders exists, considerably more research will be necessary to establish any definitive conclusions.
Ali may leave behind another legacy yet to be seen. Years later, he raised awareness about Parkinson’s, a condition that ultimately claimed his life, which may inspire even deeper studies into his terrible condition.