Oats are often touted for boosting heart health, but oat-based breakfast cereals may contain a mold-related toxin which is a possible human carcinogen, scientists say.
Some oat-based breakfast cereals in the US contain the mold-related toxin called ochratoxin A (OTA) that has been linked to kidney cancer in animal studies, researchers said.
Dojin Ryu and Hyun Jung Lee from the University of Idaho, US, said that OTA is one of the most common toxic products released by molds in the world.
Previous studies have found the toxin in samples of pork, dried fruits, wine, coffee and other products.
Scientists do not yet know how the toxin affects human health, but the International Agency for Research on Cancer, which is part of the World Health Organisation, classifies it as a possible human carcinogen.
Animals exposed to OTA in experiments have developed kidney tumours. Although the US does not currently regulate the contaminant, the European Union has set maximum limits for OTA in food.
Ryu and Lee wanted to see how US breakfast cereals - a staple in many Americans' diets - measured up to that standard.
The researchers tested close to 500 samples of corn-, rice-, wheat- and oat-based breakfast cereals purchased from US stores over two years.
They found that in most samples, OTA levels were lower than the European threshold. But concentrations exceeded the EU standard in 8 per cent of oat-based breakfast cereal samples.
The researchers concluded that oat production, storage and processing need careful review to better protect consumer health.
The research was published in ACS' Journal of Agricultural and Food Chemistry.
