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.