Pesticide Exposure Linked to Lou Gehrig’s Disease, Could Be Used to Predict Disease Risk

A blood test calculates risk through exposure to pesticides. Those with highest exposures had double the risk of developing this fatal neurological disease.

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Amyotrophic lateral sclerosis (ALS) is a fatal diagnosis with no known cure—but it may soon be more predictable.

Scientists have developed a blood test that can calculate a person’s risk of developing ALS, also known as Lou Gehrig’s disease, by measuring exposure to environmental toxins.

This breakthrough offers hope that one day doctors may be able to help people know whether they’re at risk of this disease and to better prevent someone from developing it.

ALS is a progressive disease that attacks the nervous system. With this test, those at risk because of environmental toxins may have the opportunity to change their jobs or make other lifestyle changes that could stave off a diagnosis.

Pesticide Exposure Doubles Risk of ALS

For this study, researchers analyzed more than 250 blood samples from people in Michigan with and without ALS. They calculated each person’s ALS risk and survival outlook using levels of 36 persistent organic pollutants (POPs).

POPs are hazardous chemicals that can persist in the environment for years before breaking down. They also accumulate in fatty tissue, magnifying concentrations up to 70,000 times over background levels. The risk from POP exposure is called the exposome; it refers to total exposure from external and internal sources.

Pesticide mixtures containing POPs such as polychlorinated biphenyls, which are industrial products or chemicals, and certain organochlorine pesticides, which are synthetic pesticides used in agriculture, were most associated with ALS risk, according to the study.

Participants with the highest exposures had double the ALS risk compared to those with the lowest. Moreover, the data suggest that POPs significantly impact ALS progression as well.

“Our results emphasize the importance of understanding the breadth of environmental pollution and its effects on ALS and other diseases,” Dr. Eva Feldman, director of the NeuroNetwork for Emerging Therapies at Michigan Medicine and senior author of the study, said in a statement.

The collective effect of environmental toxins, exposures, and even lifestyle factors play a “very significant role” in increasing ALS risk, Dr. Stephen Goutman, director of the Pranger ALS Clinic and associate director of the ALS Center of Excellence at the University of Michigan and first author of the study, told The Epoch Times.

“We are not yet at a stage where we can quantify the exact percentage that each toxin or a group of toxin plays,” he said. “But this is obviously an important question.”

Herbicide Exposure Already Linked to ALS

Research published in 2022 found that the increased ALS risk in people who are physically active outdoors, including farmers, gardeners, sportsmen, and women, is “intimately linked” to widely used glyphosate-based herbicides used extensively in agriculture.

However, the U.S. Environmental Protection Agency (EPA) maintains that glyphosate poses no health risk based on current use, which is for inhibiting an enzyme essential for plant growth, effectively killing a broad spectrum of weeds and unwanted plants. Glyphosate-based weed killers are being sprayed on almost half the planted acres in the United States.

The EPA’s safety limits for glyphosate exposure from food are five times the levels allowed by the European Union.

Other environmental factors tied to higher ALS risk include exposure to heavy metals such as mercury, manganese, copper and, especially, lead.

Dr. Goutman’s studies show that environmental toxins significantly impact ALS risk and progression, he said, noting that exposure to multiple ALS-associated toxins significantly increases risk versus just one.

“This tells us that further work is needed to better understand how the exposome influences ALS and how we can eventually leverage this knowledge to inform ALS treatment and prevention strategies,” Dr. Goutman said.

ALS Rates Projected to Significantly Increase

ALS rates are projected to rise by 70 percent worldwide by 2040, according to University of Michigan Health. Other key facts include the following:

• Worldwide, someone is diagnosed with or dies from ALS every 90 minutes.
• In 90 percent of cases, ALS occurs without a family history.
• Onset is typically between ages 40 and 70.
• Life expectancy after diagnosis is two to four years.

Currently, treatment only slows ALS progression and may include medication and physical or occupational therapy. As ALS advances, walking, speaking, eating, and breathing become increasingly difficult.