Human Study on the Kinetics of 2′ R ‐Ochratoxin A in the Blood of Coffee Drinkers

Scope The aim of this study is to obtain a deeper knowledge of the kinetics of 2′ R ‐ochratoxin A (2′ R ‐OTA), the thermal degradation product of the mycotoxin ochratoxin A (OTA). To investigate the correlation between the amount of this compound in roasted coffee and human blood samples, a human study is performed. Methods and Results An 18‐week human study is carried out. During the first eight weeks, all known 2′ R ‐OTA‐containing food sources are excluded from the diet and the reduction of 2′ R ‐OTA in venous blood is analyzed. Afterwards, participants are allowed to consume coffee with known OTA and 2′ R ‐OTA concentrations. On a biweekly scale, 2′ R ‐OTA and OTA blood levels are determined. After eight weeks of fasting on 2′ R ‐OTA‐containing foods, the 2′ R ‐OTA blood concentration decreased by about 10%. Based on this, a long biological half‐life of over seven months is estimated. In the 24 h urine samples collected before and after the coffee fasting period, only traces of 2′ R ‐OTA are detected. Conclusion Results show that 2′ R ‐OTA has a more than seven‐fold higher biological half‐life in human blood compared to OTA (approx. 35 days). The reason for the long persistence of 2′ R ‐OTA in human blood is still unclear and further research is needed.