Effect of Eating Time on Lycopene Bioavailability in Rats and Humans

Abstract

Lycopene, a major carotenoid in tomato, is one of the strongest natural singlet-oxygen quenchers. Circadian rhythms have been suggested to affect the bioavailability of many nutrients, but no previous studies have investigated such effects on lycopene. Therefore, we investigated the effects of the timing of lycopene ingestion on its bioavailability in both rodents and humans. Rats or healthy human subjects consumed lycopenecontaining test food at different times, and their blood lycopene concentrations were then measured. It was found that the increase in blood lycopene level was highest when lycopene was ingested at the beginning of the active period in rats or in the morning in humans. The result appeared to depend on not only the time slot chosen but also the length of the adjacent fasting period. Our findings suggest that the bioavailability of lycopene is maximal at breakfast because it follows a period of fasting.