The Effect of an Iron Supplement on Lycopene Metabolism and Absorption During Digestion in Healthy Humans.

Abstract

To investigate the formation and absorption of lycopene (LYC) metabolites in the human upper gastrointestinal lumen, in the absence and presence of iron. Healthy males (n = 7) consumed test meals that deliver ≈22mg LYC + ≈0.3mg apo-lycopenals from oleoresin without (-FeSO4 ) and with ferrous sulfate (160mg, +FeSO4 ). Subjects were intubated with a naso-gastric/naso-duodenal tube. Digesta, blood plasma, and the triglyceride-rich lipoprotein (TRL) fractions of plasma were analyzed using LC-MS/MS, to measure LYC and apo-lycopenoids. Digesta LYC concentrations increased with time (p = 1.2×10-7 ), decrease with time×iron (p = 1.1×10-5 ), and remain ≈200× higher than apo-lycopenals/lycopenone. Digesta apo-8'-, -10'-, -12'-, -14'-, -15-lycopenal, and apo-13-lycopenone concentrations increased with time (p <0.01), apo-12'-, -14'-, -15-lycopenal, apo-13-lycopenone increase with iron (p <0.05), and time×iron decrease apo-8'-, -10'-, -12'-, -14'-, -15-lycopenal, apo-13-lycopenone concentrations (p <0.01). A 1.9-fold decrease in LYC TRL area-under-the-time-concentration-curve is observed after the test meal +FeSO4 versus the test meal -FeSO4 (p = 0.02). Apo-lycopenals were detected in later TRL fractions, and no apo-lycopenols or apo-lycopenoic acids were observed in any samples. FeSO4 reduces LYC absorption. Apo-lycopenals appear to be absorbed from foods, and not made in significant quantities during digestion.