Terence Monmaney of Popular Science reports that in Montchavin, a small village in the French Alps, a rare cluster of ALS (amyotrophic lateral sclerosis) cases has drawn attention from medical researchers. Over a decade, 14 people in this otherwise sparsely populated area developed ALS, a condition usually linked to genetics or environmental factors. The investigation by neurologist Emmeline Lagrange, along with collaborators, found no genetic links but discovered a possible environmental cause: the consumption of false morel mushrooms, which contain neurotoxic compounds. This finding parallels an earlier ALS epidemic in Guam, where cycad seeds were linked to the disease. While researchers caution that further studies are needed, they recommend public awareness about the dangers of false morels. Monmaney writes:
The road switches back and forth again and again as it climbs into Montchavin, perched in the French Alps at 4,100 feet above sea level. The once-sleepy mountainside village, developed into a ski resort in the 1970s, is dotted with wooden chalet-style condo buildings and situated in the midst of a vast downhill complex known as Paradiski, one of the world’s largest.
Well known to skiers and alpinistes, Montchavin also has grabbed the attention of medical researchers as the site of a highly unusual cluster of a devastating neurological disease, amyotrophic lateral sclerosis.
ALS, brought about by the progressive loss of nerve function in the brain, spinal cord and motor neurons in the limbs and chest, leading to paralysis and death, is both rare and rather evenly distributed across the globe: It afflicts two to three new people out of 100,000 per year. Though Montchavin is flooded with visitors in winter and summer, the year-round resident population is only a couple hundred, and neighboring villages aren’t much bigger, so the odds are strongly against finding more than just a few ALS patients in the immediate area. Yet physicians have reported 14.
The first of the village patients to arouse suspicion in Emmeline Lagrange, the neurologist who has led the investigation into the problem, was a woman in her late thirties, a ski instructor and ski lift ticket-checker originally from Poland who worked in the offseason at the local tourism office. It was 2009. […]
Lagrange didn’t expect to find other ALS cases in the vicinity. But a newspaper story about efforts to raise money for a man who needed a wheelchair led her to one patient. A pharmacist helped her to find another. Lagrange recalls being “very afraid” as the cases added up: another in 2009, three in 2010, two in 2012, one each in 2013, 2014, 2015, the last in 2019. Ultimately, she identified 16 ALS cases, though only nine men and five women agreed to be further studied. Lagrange herself examined 13 of them. Their age at diagnosis ranged from 39 to 75. […]
Looking back, Lagrange says in an interview, “We were at a stop. We had no more ideas.”
Yet the abstract contained one phrase that would prove pivotal: Six of the patients, it said, “used to eat local mushrooms.” […]
Lagrange and coworkers learned that the ALS patients had deliberately sought out false morels for their supposed “rejuvenating” properties as well as their flavor. Indeed, the ALS patients knew one another and actively shared information about where to find the fungi. “They are always in a group, a secret group, a social network, and they eat the mushrooms,” a village elder explained to Lagrange. “And they all knew that it’s forbidden.”
Significantly, half of the French ALS patients had previously become acutely ill after consuming what they described as morels.
To show that the consumption of false morels and the development of ALS in this group was more than a mere coincidence, the researchers broadened their study to include a control group: 48 people from the same area who were roughly the same ages. Control subjects also ate wild mushrooms — but not false morels. There are plenty of species of false morel, but the best known and most poisonous is Gyromitra esculenta, one of the types collected and consumed by patients in the Montchavin ALS cluster. […]
“It looks like something from an alien movie, but it’s delicious,” Kim Mikkola, then the chef of a Michelin-starred restaurant in Helsinki, said in a 2020 video that showed him collecting and preparing false morels. He says the fungi do contain neurotoxins and demonstrates the detoxification process. “If treated right it’s very good, acidic and a bit nutty. It has that kind of forest mushroom flavor … a very elegant delicacy.”
In North America, false morels also have appeal, at least among a subset of foragers. “It may surprise you that Gyromitra esculenta is considered a delicacy in parts of the United States and in parts of Scandinavia,” one blogger notes. But a physician writing in the US-based magazine Fungi in 2020 cautioned that people who persist in eating false morels are merely “winning in a game of Russian roulette.” […]
A “growing body of literature has evoked concern regarding an insidious, chronic toxicity associated with gyromitrin exposure and a potential link to neurodegenerative disease,” the Michigan team wrote in their paper. “Future research is needed to explicate the nature of these associations, especially considering the high prevalence of ALS in the Midwest US and the regional popularity of [morel] consumption.” In its most recent analysis of ALS in the population, the Centers for Disease Control and Prevention ranked Michigan as No. 6 in the United States, with an age-adjusted prevalence of 5.3 cases per 100,000 population (the US average was 4.4).
The challenge of establishing cause and effect in neurodegenerative disease is steeper than the winding road into Montchavin. Spencer and others realize the difficulty, particularly with all the years stretching between exposure and disease onset. And retrospective evidence seldom convinces everyone. As a clinical neurologist, Lagrange acknowledges that she isn’t equipped to perform the kinds of cell culture, animal modeling and genetic studies that would take the argument to the next level. Her colleague Camu, however, has started testing their ideas in lab mice.
For now, she says in a Zoom interview, “I think I did the job. I’m just a little doctor” — she holds her thumb and forefinger about an inch apart — “worried about the possibility of new cases in the village.”
And there have been no new cases of ALS, she says. “Hopefully, there’s no more.”
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