A deadly toxin, Hypoglycin A, has been found in some milk samples from Northern Germany. The toxin is known to be present in high concentrations in the seeds and sprouts of various maple trees, including the widely distributed Norway maple in Germany. Hypoglycin A can cause severe illness and even death in humans. In 2017, several hundred children in India died suddenly after consuming large quantities of lychees, which contain the toxin. The substance disrupts the body’s energy metabolism, leading to a very low blood sugar level, a typical symptom in humans. The toxin has also been found to cause a fatal disease in horses called Atypical Myopathy.
Researchers from the Martin Luther University Halle-Wittenberg and the Leibniz Institute for Plant Biochemistry have investigated whether cows grazing on pastures with maple trees could also be exposed to the toxin. The team collected milk samples from various farms in Northern Germany and used a special mass spectrometry method to detect even the smallest amounts of the toxin. They found Hypoglycin A in raw milk samples from a farm where a maple tree was present on the pasture. The concentration ranged from 17 to 69 micrograms per liter of milk. Although the concentrations were low and varied, the researchers were surprised to find any trace of the toxin at all, given that the samples were from a collective tank and not from individual cows.
This study is the first to show that cows can apparently absorb the toxin from the plant parts of the Norway maple and transfer it to their milk. The researchers now plan to investigate how much of the toxin cows need to ingest to produce detectable concentrations in their milk. They also want to determine whether the standard treatment of milk and processing into food destroys the toxin. It is still unclear whether the low concentrations of the toxin in the milk pose a risk to cows or humans.
