Growing mycotoxin levels in European wheat, new study says

According to a new study, conducted by the University of Bath in collaboration with the University of Exeter, the harmful fungal infection known as Fusarium Head Blight (FHB) is on the rise across Europe, affecting almost half of wheat crops and placing human and animal health at risk.  

The research team, led by Dr Neil Brown, examined the largest monitoring datasets available for Fusarium mycotoxins that were made accessible by governments and agribusiness, paying particular attention to wheat grain entering the food and feed supply chains in Europe.  

The researchers used data collected across Europe (including the UK) during the last 10 years and created the most comprehensive picture yet of the mycotoxin threat and its evolution in space and time.  

Fusarium mycotoxins were discovered in every European country.  

Even if FHB is a seasonal disease, the researchers observed that since 2010, mycotoxin levels in years with high disease incidence have gotten worse in the Mediterranean area.  

The study highlights that half of the wheat grown for human consumption in Europe contains deoxynivalenol (DON, known also as “vomitoxin”, the mycotoxin produced by Fusarium fungi). In the UK the situation is even worse, with 70% of wheat contaminated.  

The increase in mycotoxins in wheat is thought to be largely due to changes in farming, such as soil preservation practices that give the Fusarium fungus the perfect environment to grow, as well as climate change.  

Governments set legal limits of DON contamination levels in wheat destined to human consumption. Thanks to these regulations the consumers are protected, as 95% of wheat destined to our tables meet the safety limits. However, considering the ubiquity of mycotoxins, “there are real concerns that chronic dietary exposure to these mycotoxins impacts human health.” said Dr Brown.  

Another alarming discovery was the presence of other Fusarium toxins in 25% of the food wheat that contained DON (and it can be assumed that this is an underestimation, since not all wheat is routinely tested for other toxins). Moreover, according to the researchers, the simultaneous presence of different toxins interacting with each other could have more harmful effects on our body than any toxin would alone.  

The authors of the study also found high levels of DON mycotoxin in wheat fed to livestock, and that’s because when mycotoxins reach a certain level, the contaminated grain is diverted from human food to animal feed. “This comes at a cost to the cereal farmer, impacts cereal market prices, and shifts the health problem to our livestock.” said Dr Brown.  

The researchers evaluated the economic impact of FHB toxins (done by estimating the value lost due to wheat being too contaminated with DON for human consumption): 3 000 million euros over the last ten years.      

With their study, the authors hope to stimulate further research aimed at developing better ways to protect crops against fungal pathogens, because, as Dr Brow said, “it is the only way for us to successfully mitigate the negative economic and health impacts of mycotoxins.”