New Study Shows Pesticide Exposure May be Linked to Lou Gehrig's DiseaseMay 16, 2016
A new study reports that repeated exposure to common pesticides may influence the chance of developing amyotrophic lateral sclerosis (ALS), commonly known as Lou Gehrig's disease, a debilitating and fatal condition.
The name Lou Gehrig's disease comes from the New York Yankees' first baseman whose career was ended by ALS in 1939. ALS is a progressive and ultimately fatal disease in which the motor neurons deteriorate leading to muscle weakness and paralysis. Victims gradually lose the ability to initiate muscle movement and this leads to the inability to speak, eat, move, and breathe, typically within three to five years of diagnosis, Medical Daily reports. Currently, there are no treatments that can halt or reverse the damage and there is little that can be done to help patients maintain their quality of life.
In looking for environmental factors that might be involved in the risk for ALS, researchers from the University of Michigan investigated exposure to various pesticides. In a three-year period from 2011 to 2014, the researchers studied 156 patients with ALS and a control group of 128 patients without ALS. All the participants lived in Michigan. Every participant provided blood samples and completed a detailed survey of their exposure to pesticides. The results shows that those who reported higher pesticide exposure had a "significant" increase in their risk for ALS compared to those who did not have such exposure. The findings were published in JAMA Neurology.
The participants at risk had blood concentrations with elevated levels of environmental pollutants, including organochlorine pesticides (OCPs), polychlorinated biphenyls (PCBs), and brominated flame retardants (BRFs). The traces of pesticides found in the subjects' blood samples are chemicals used to protect crops and livestock from farming pathogens and insects that can damage or destroy them, Medical Daily reports.
OCPs are broken down into five different chemical groups, one being the once widely used DDT (dichloro-diphenyl-trichloroethane), banned by the Environmental Protection Agency (EPA) in the 1970s after their link to numerous health risks in both humans and animals was discovered. The Center for Environmental Research & Children's Health reports that PCBs are also linked to an increased risk of cancer, and they last for a long time in the human body. PCBs accumulate in fat and are often found in breast milk, according to Medical Daily. In 2003, a study in Environmental International warned that BRFs-a mixture of industrial chemicals used to make products less flammable-are potential carcinogens that also alter reproductive organs, liver, and thyroid hormones.
The researchers do not know how pesticides trigger ALS, if they do. But further research into such a link is urgently needed: ALS.net reports that someone in the U.S. is diagnosed with ALS approximately every 90 minutes.
The Michigan researchers plan to look further into the risk factors of exposure to pesticides. They will look at different chemicals and how they affect ALS patients on a cellular level. "[A]s environmental factors that affect the susceptibility, triggering and progression of ALS remain largely unknown, future studies are needed to evaluate trends in exposure measurements, assess newer chemicals, consider mechanisms, and assess variations," the authors conclude.