Organic food has the aura of healthy living – but can organic vegetables give you a bad case of food poisoning… or worse?
Spanish scientists have found that tiny amoeba that live on vegetables can ‘shelter’ harmful bacteria such as salmonella, which researchers describe as a ‘Trojan horse’.
They found that the contamination included bacteria that can cause severe digestive illness, as well as amoebas that can also cause blindness.
The finding means that people who eat organic leafy vegetables may be at risk of disease, said researchers from the Universitat Polytechnica de Valencia.
He said the risk is particularly high with leafy greens because they are often eaten unwashed.
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The danger comes when leafy organic vegetables come in contact with manure or sewage and become contaminated.
Vegetables can be contaminated with single-celled organisms such as free-living amoeba (FLA), which feed on the bacteria – but some bacteria resist FLA digestion and pose a threat to human health.
Lead author Dr Yolanda Moreno, from the Universitat Politecnica de Valencia, said: “The presence of bacteria of public health concern contained inside free-living amoebae suggests that they are vehicles that can easily transmit pathogens capable of reaching humans. and can cause health problems.Contaminated organic vegetables
“Contamination can arise as a result of treating soil with organic fertilizers such as manure and sewage sludge and irrigation water.
“Leafy greens are particularly susceptible to faecal contamination because of their proximity to the ground and the possibility of them being consumed by humans without cooking.
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“Our results also emphasize the need to educate the public on the safe and proper handling of fresh organic vegetables before eating them fresh or slightly cooked.”
The researchers used a metagenomic technique that identifies the DNA in all bacteria present inside the FLA.
One-third of the samples (34%) contained 52 potentially disease-causing bacteria, including Legionella, Salmonella and Arcobacter.
The resulting infection can cause conditions including pneumonia and gastrointestinal illness.
The FLA species Vermoiba vermiformis, which commonly causes severe infections in humans, was found in one fifth (19%) of the vegetable samples; and Acanthamoeba Castellanii, which can cause blindness and encephalitis, were identified in about two-thirds (63%) of the samples.
Despite the findings, the authors noted that the study only included a small sample of leafy organic vegetables from one city in Spain, and that larger studies from different countries are needed to understand more about the microbiological quality and safety of organic vegetables. Is.
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This follows research in 2018 that warned that organic vegetables were harming our climate.
Scientists at Chalmers University of Technology in Sweden calculated the impact of the amount of land used for organic farming, which could lead to deforestation elsewhere in the world.
They found that products such as peas grown organically in Sweden have a 50% greater impact on the environment than non-organically farmed food.
The reason organic food is so bad for the climate is that the yield per hectare is so low, mainly because fertilizers are not used.
To produce the same amount of organic food, you need a large area of land – and that has a worldwide impact.
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