Though previous studies have linked serious head injury and pesticide exposure to Parkinson’s disease, the combination of both may be an even greater risk, a new study shows.
The study led by researchers at the University of California at Los Angeles is published in the November 13 print issue of Neurology®, the medical journal of the American Academy of Neurology.
“While each of these two factors is associated with an increased risk of Parkinson’s on their own, the combination is associated with greater risk than just adding the two factors together,” said study author Beate Ritz, MD, PhD, UCLA’s Fielding School of Public Health, in a media release. “This study suggests that the physiological process that is triggered by a head injury may increase brain cells’ vulnerability to attacks from pesticides that can be toxic to the brain or the other way around, for example, chronic low dose exposure to pesticides may increase the risk of Parkinson’s after a head injury.”
The study involved 357 people who had Parkinson’s disease and 754 people without the disease, all of whom lived in an agricultural area in central California, according to the release.
Researchers asked participants to report any head injuries they had ever received with a loss of consciousness for more than five minutes. They used data on the use of the herbicide called paraquat collected by the state of California’s Pesticide Use Reporting system to determine exposure to the weed killer based on a 500-meter area around their home and work addresses.
From this data, they found that individuals with Parkinson’s were twice as likely to have had a head injury with loss of consciousness for more than five minutes, and that people with Parkinson’s disease were 36 percent more likely to have exposure to paraquat than those who did not have the disease.
The new study doesn’t prove that a traumatic brain injury or pesticide exposure causes the disease. What it shows is that having a head injury along with living near areas where the pesticide called paraquat is used may lead to triple the risk of developing Parkinson’s disease.
As many as one million Americans live with the progressive neurodegenerative disease that may cause tremors in the body - more than the combined number of people diagnosed with multiple sclerosis, muscular dystrophy and Lou Gehrig’s disease, according to the Parkinson’s Disease Foundation.
"I think all of us are beginning to realize that there's not one smoking gun that causes Parkinson's disease,” Dr. James Bower, a neurologist from the Mayo Clinic in Rochester, Minnesota, who wasn't involved in the new research, said in a Nov. 13 article from Reuters Health news wire. "There might be many paths to the ultimate development of Parkinson's disease."
He added that “. . . some people who are genetically predisposed might need just one ‘environmental insult’ - such as a blow to the head - to set them up for Parkinson's. Others who aren't naturally susceptible to the disorder could still develop it after multiple exposures.”
No comments:
Post a Comment