Study Finds Link Between Head Injuries, Pesticide and Parkinson’s Disease

A new study suggests that head injuries and exposure to certain herbicides may increase the risk of Parkinson’s disease. 

Researchers from the University of California at Los Angeles published a report in the medical journal Neurology this month, which presented findings that indicate when someone suffers a traumatic brain injury (TBI) and are exposed to paraquat, one of the world’s most commonly used herbicides, their risk of Parkinson’s disease triples.

The study looked at data on more than 1,100 people from 2001 to 2011, 357 of whom had been diagnosed with Parkinson’s disease. They found that those who suffered TBIs had twice the risk of developing Parkinson’s disease as the general populace. The increase from paraquat exposure alone was very small by comparison. However, when someone who lived in an area with high levels of paraquat use and had a TBI, their risks of a Parkinson disease diagnosis tripled.

“These environmental factors seem to act together to increase PD risk in a more than additive manner,” the researchers determined.

A traumatic brain injury can be the result of a blow to the head, a jolt or a mere bump on the head, many times leading to a concussion. These types of injuries are classified as head injuries that result in a disruption of the normal function of the brain.

Not all head injuries result in this disruption and are classified as traumatic brain injuries. A mild brain trauma causes a brief change in the disruption of the normal functioning of the brain, while a severe case will disrupt the functioning of the brain for long periods of time.

According to the U.S. Centers for Disease Control and Prevention (CDC), nearly 1.7 million people suffer from a traumatic brain injury every year and traumatic brain injuries contribute to 31 percent of all injury-related deaths in the United States.

The side effects of TBI can include cognitive problems, memory loss, loss of senses such as taste, smell and touch, depression, anxiety, and in some cases can change a person’s personality.

A study published in September also linked TBIs to an increased risk of Alzheimer’s disease due to elevated levels of an enzyme called BACE 1 after a head injury.