Why Americans who live near coastlines and lakefronts may face heightened ALS risk

If you live near bodies of water frequently impacted by harmful algal blooms, you may be at an increased risk of dying from ALS, new research reveals.

Amyotrophic lateral sclerosis, the debilitating neurodegenerative disease commonly known as “Lou Gehrig’s Disease,” is influenced by genetics and environmental factors. It dramatically slashes the patient’s life expectancy, with people typically passing away within two to five years of diagnosis.

Some 5,000 are diagnosed with ALS each year in the U.S., and there are approximately 15 new cases each day. Recently, Grey’s Anatomy star Eric Dane announced he was battling the disease and told Good Morning America that his body’s right side had “completely stopped working.”

Now, researchers at the University of Michigan Medicine say toxins produced by algal blooms in lakes and along American coasts could influence disease progression.

“While there is still limited research into the mechanism by which cyanobacteria toxins affect neurodegenerative diseases, our findings suggest that living near or participating in activities in these water bodies may influence the progression of ALS,” Dr. Stephen Goutman, the school’s Harriet Hiller research professor, director of the Pranger ALS Clinic, and associate director of the ALS Center of Excellence, said in a statement.

Goutman is the senior author of the study which was published in the International Journal of Environmental Research and Public Health.

Specifically, the researchers have found a toxin produced by the bloom cyanobacteria in brain and spinal fluid cerebral spinal fluid samples of people with ALS. It’s known as ß-methylamino-L-alanine.

Increasingly driven by human-caused climate change and nutrient pollution, the blooms are caused when cyanobacteria grows dense and out of control. Cyanobacteria produce several toxic agents that are linked neurodegenerative diseases, including Alzheimer’s and Parkinson’s.

They surveyed participants who were seen at the University of Michigan Pranger ALS Clinic, many of whom lived within three miles of a harmful algal bloom. They measured the duration and extent of their exposure using satellite data from the Cyanobacteria Assessment Network and their residential and health histories.

Ultimately, they found that living near blooms — especially if swimming or boating — was associated with dying of ALS nearly one year sooner. The people with the most significant exposures both lived near harmful blooms and used a private well as their water source.

People in the Midwest may be particularly threatened partially due to pervasive industrial and agricultural productions in the region. Michigan’s Lake Erie is frequently impacted by these blooms.

“If exposure to cyanobacteria toxins is a meaningful risk factor for ALS, the large number of inland lakes from to such bacteria in the Midwest may partly explain why the disease incidence is much higher than other parts of the country,” Dr. Stuart Batterman, first author and professor of environmental health sciences at the university’s School of Public Health, said.