For centuries, foragers in parts of Europe have prized a strange looking mushroom called the false morel. Its unusual folds and earthy flavor have earned it a place at the table in mountain villages and, more recently, among adventurous food lovers who seek out rare ingredients. But new research from France suggests that this culinary tradition may carry a hidden risk: a possible link to Lou Gehrig’s disease, also known as ALS.
A Cluster That Caught Attention
The alarm was raised in Montchavin, a small village in the French Alps. Over the span of several decades, doctors noticed a troubling pattern. Far more residents than expected were being diagnosed with ALS, a progressive disease that attacks nerve cells in the brain and spinal cord. The numbers stood out sharply against the background rate in the general population.
Researchers began asking questions. Was there something unusual in the water, in the soil, or in local customs? After years of investigation, one habit kept surfacing: many of the patients had eaten false morels gathered from nearby forests.
What the Study Found
A team led by French researcher Xavier Lagrange set out to look more closely. Their study, published in 2024, did two things. First, it carefully identified the mushrooms that villagers had been consuming. What had once been assumed to be a relatively harmless species turned out to be other varieties of false morel that are known to contain higher amounts of a toxin called gyromitrin.
Second, the researchers looked at who was getting sick. They found that many ALS patients carried a genetic trait that makes it harder for the body to process certain toxins. Taken together, the findings raised the possibility that repeated exposure to false morels, combined with slower detoxification in some individuals, could contribute to the disease.
What the Study Did Not Prove
It is important to note that the study did not prove causation. The researchers reported an association between mushroom consumption and ALS in this one community, not definitive proof that one leads to the other. The number of people studied was small, and there could be other factors at play that scientists have not yet uncovered.
In other words, the study makes a strong case for caution but not for certainty. Eating false morels may increase risk, especially for certain people, but the exact mechanism and the true level of danger remain open questions.
What We Already Know About ALS
ALS has long been one of the most puzzling neurological diseases. About 5 to 10 percent of cases are linked to inherited genetic mutations, but the vast majority are considered “sporadic,” meaning no single cause is clear. Researchers have connected ALS risk to factors such as military service, exposure to certain heavy metals, pesticides, and smoking. Chronic head trauma has also been studied. Yet even with these associations, most cases remain unexplained. This is why clusters like the one in Montchavin are so valuable for research — they offer a chance to look for specific environmental triggers that might push some people toward the disease.
A Parallel in Guam
The situation in France echoes another medical mystery half a world away. In the mid-20th century, doctors documented unusually high rates of ALS and related disorders among the Chamorro people of Guam. Later research linked the outbreak to a traditional food source: seeds from the cycad plant, which contain neurotoxic compounds. For years, Chamorro families ate flour and even flying fox bats that had consumed the seeds, leading to chronic exposure. Once diets shifted and the exposure declined, the ALS rates in Guam also fell.
While the toxins are different, the storylines are strikingly similar: a unique food tradition, an unusual cluster of cases, and the possibility that environmental exposure interacts with human biology to trigger a devastating disease.
What We Know Since
Other studies in recent years have added pieces to the puzzle but have not closed the case. A 2021 report first described the Montchavin cluster and linked it to mushroom consumption. The 2024 follow-up clarified which species were involved and provided more evidence of a genetic factor that might explain why some people are more vulnerable.
Beyond ALS, scientists have speculated whether mushroom toxins might play a role in other neurological diseases, such as Alzheimer’s, but no direct evidence has been found. For now, the conversation remains centered on ALS.
Why It Matters
ALS has long puzzled researchers. In most cases the cause is unknown, and clusters like the one in Montchavin are rare. When they appear, they provide valuable opportunities to explore environmental triggers. Even if false morels turn out not to be the main culprit, the study reminds us that food traditions, no matter how longstanding, can sometimes harbor risks that only become visible years later.
Looking Ahead
More work will be needed to confirm or disprove the connection. Larger studies, both in France and elsewhere, could test whether communities that consume false morels regularly show higher rates of ALS. Laboratory experiments may also help clarify how mushroom toxins interact with human biology over time.
For now, public health officials in Europe already caution against eating false morels, even when they are cooked. Boiling can reduce toxins, but some remain, and the long-term effects are still unclear.
The Bottom Line
The French study has opened an intriguing line of inquiry into how a beloved food might intersect with a devastating illness. It has not closed the case, but it has put a spotlight on a mushroom that is both delicacy and danger. For science, it is a reminder that the dinner plate can be a window into disease. For the rest of us, it may be a reason to pause before chasing culinary thrills deep in the woods.
