Nut cheeses are often marketed as safer than raw-milk dairy cheeses for vulnerable people, but that’s not necessarily the case.
Vegan cheeses have been identified as the cause of a listeriosis outbreak in Europe in 2022.
The L. monocytogenes bacterium affected four pregnant women in France who gave birth prematurely and an immuno-compromised 38-year-old who developed meningoencephalitis, as well as a three-year-old in Belgium, a person with pregnancy-associated sepsis in Germany and a maternal-neonatal case of neonatal meningitis in the Netherlands.
The link between the recent illnesses and the “incriminated products”, imported into Europe and sold in shops and online, was proven through genetic profiling of the listeria monocytogenes clinical isolates, said the authors of the correspondence published in the New England Journal of Medicine.
“Such products are promoted as being healthier to consume than dairy cheeses and free of zoonotic foodborne pathogens because they are plant-based. However, these products did not undergo a hygiene step such as pasteurisation that could control contamination at the level of raw materials or from a contaminated production or postproduction environment,” they wrote.
Vegan cheeses are made from raw almond, cashew or coconut milk and resemble semi-soft dairy cheeses such as Camembert, goat cheese and blue cheese.
The bacterium L. monocytogenes, which causes listeriosis is well known to contaminate raw meat, dairy, fish, seafood and vegetables, but it can also contaminate raw fruit and nuts.
“In a study in which L. monocytogenes was inoculated in beverages derived from nut milks and in bovine milk, the proliferation of bacteria was greater in the plant-based milks. The physicochemical properties of these products (e.g., pH and water activity) allow the growth of L. monocytogenes,” the authors explained.
This is not the first dangerous bacterial contamination of vegan cheeses. They have also been linked to salmonella outbreaks in the US in 2021 and as far back as 2014.
However, “vegan cheese substitutes continue to be inappropriately marketed as a safe alternative to raw-milk dairy cheese to populations at increased risk for foodborne infection, such as pregnant persons,” the authors said.
“This outbreak highlights both the lack of data on the contamination of these products by foodborne pathogens, including L. monocytogenes, and the need for manufacturers of vegan cheese substitutes to consider this risk in their production processes, as with any other ready-to-eat product,” they wrote.
Vegan cheese suppliers are subject to the same standards for food safety as every other Australian food business, Food Standards Australia New Zealand (FSANZ) told TMR.
According to their data, product recalls because of microbial contamination account for 25% of food product recalls between 2013 and 2022 and the trend is increasing, probably due to greater oversight. Of those 194 recalls, 70 were about L. monocytogenes (36%) followed by 44 for salmonella (23%) and 38 for E. coli (20%).
Perhaps surprisingly, after mixed/processed foods (a very broad category) the next-most commonly food category recalled for any reason was fruit, vegetables and herbs, with dairy products coming in third. No vegan cheeses were recalled during the data collection period.
