Red yeast rice derives from rice inoculated with fungi and produces compounds which are able to inhibit cholesterol production and maintain it at healthy levels. It has been used as a natural dietary supplement for thousands of years in some Asian countries and is nowadays considered as a true food supplement worldwide. Red yeast rice also improves digestion and blood circulation. It has been promoted to contribute to public health by reducing the risk of heart disease among individuals showing moderate increases in cholesterol levels. Red yeast rice exists in forms: powders to be taken in small quantities or as food supplements marketed in doses such as capsules, tablets, pills. 

However, besides the classical cholesterol lowering compound, a natural toxin (citrinin) is often co-produced during the fermentation process of red yeast rice. The toxin has been associated with kidney diseases and may exhibit genotoxic and carcinogenic effects in several animals. The more recent scientific assessment realised by the European Food Safety Authority (EFSA) concluded that red yeast rice food supplements samples could lead to contamination with citrinin, as the European Union’s legal limit of 2,000 μg/kg was exceeded.

Recently, results from studies conducted in Germany and Belgium have showed that citrinin and/or its metabolite ‘dihydrocitrinone’ can be detected in up to 90% of the human urine samples collected, indicating that the exposure to this toxin might be more important than it has been assumed so far. This shows that the population is chronically exposed to low citrinin levels, without a clear knowledge of the potential risk.

There is overwhelming evidence of global contamination of red yeast rice with citrinin. Literature does recall several cases of capsules of red yeast rice contaminated with citrinin available on the market, with concentrations ranging from 2 to 114 μg of citrinin/capsule. Recently, red yeast rice has clearly been identified in a European survey as the product with the highest incidence of citrinin contamination. Of the 37 samples surveyed, citrinin has been quantified in 24 red yeast rice food supplements with concentrations ranging from 10 to 3,597 μg/kg. It has been detected in 13 samples below the quantification limit of 10 μg/kg. Although it was labelled that the origin of the samples was Europe, it is not clear whether the raw materials came originally from Europe or if they were processed there. Three of the samples were above the European Union legal limit of 2,000 μg/kg. In Belgium, low levels of citrinin were found in the samples of red yeast rice and food supplements collected, but a high level of citrinin (up to 121 mg/kg) has been found in one foreign red yeast rice sample which exceeded the maximum acceptable level fixed for European countries.