Lack of hygiene

Listeria detected in vegan cheese for the first time

For the first time, scientists have clearly proven cases of listeriosis caused by vegan cheese products in several European countries.

(Bild: Krone KREATIV,)

Listeria in red mold cheese, Quargel etc. is a "classic". But now, for the first time, scientists have clearly proven cases of listeriosis caused by vegan cheese products in several European countries. They have reported their findings in the "New England Journal of Medicine".

"Vegan cheese substitutes have been recommended as an alternative to raw milk cheese for people at risk of listeriosis infection - including pregnant women. We report an outbreak of listeriosis in France between April and December 2022 that affected four pregnant women who suffered premature births (on average after 32 weeks of gestation) and the case of a 38-year-old person with a compromised immune system who developed meningoencephalitis (inflammation of the brain and meninges; ed.)," wrote Alexandre Leclercq from the Institut Pasteur in Paris and his co-authors in the world's most prestigious medical journal a few days ago (DOI: 10.1056/NEJMc2400665).

Vegan cheese substitutes have often been recommended as an alternative to raw milk cheese.

(Bild: stock.adobe.com)

Several cases in Europe
Following a warning from the French authorities, further cases were discovered in Belgium (in a three-year-old child), in Germany (in a person with pregnancy-associated sepsis) and in the Netherlands (meningitis in a baby after birth), the German medical journal Deutsches Ärzteblatt has now also written. The scientists sequenced the genetic material of the listeria that had caused the severe infections: The bacteria were effectively identical. When questioning those affected, it emerged that they had consumed vegan "Jay & Joy" cheese from a French manufacturer. In January 2023, the producer recalled several varieties of the brand.

The product recall affected a vegan goose liver substitute product as well as substitute products for Brie or blue cheese. "Made from raw almond, cashew or coconut milk, these alternative semi-soft substitutes imitate other dairy products (e.g. Camembert, goat and blue cheese)", wrote the scientists involved in the investigation of the affair.

"No hygiene measures"
One potential problem, according to the experts: "Such products are marketed as healthier than cheese made from (animal; note) milk and as free from food-borne pathogens because they are plant-based. But they are not subjected to hygienic measures such as pasteurization to control contamination in the raw material, during production or after production."

Such products are marketed as healthier than cheese made from (animal; note) milk and free from food-borne pathogens because they are plant-based. But they are not subjected to any hygiene measures such as pasteurization to control contamination in the raw material, during production or after production.

Die Wissenschaftler über Käseersatzprodukte

It appears that milk from plant sources is also potentially a good breeding ground for listeria. In a comparative study cited by Marc Lecuit (Institut Pasteur/Paris) in the New England Journal of Medicine, listeria even grew significantly faster in milk produced from nuts than in cow's milk (Food Microbiology 2023; DOI: 10.1016/j.fm.2022.104143).

The physico-chemical properties of these products (such as pH value and water activity) would enable the growth of L. monocytogenes, Lecuit continued. At least in the United States, the vegan substitute products continue to be inappropriately promoted as safe alternatives to raw milk products of animal origin. Salmonella contamination has also been detected. Manufacturers should also be aware of the risks of pathogens in vegan cheeses.

Listeria can cause life-threatening infections
Listeria is known to be able to trigger life-threatening invasive infections, particularly in older people or those with weakened immune systems. Only recently, the manager of a cheese dairy in Wiener Neustadt, which has since been closed, was tried in criminal court for listeria cases (grossly negligent homicide in five cases and grossly negligent grievous bodily harm in two cases) and sentenced to 13 months in prison.