Effect of lutein on beta-carotene absorption and cleavage.

Carotenoid interactions during absorption and in postabsorptive metabolism have been observed in both human and animal studies. We reviewed the mutual interactions reported between lutein and beta-carotene and report new data on the postprandial beta-carotene and retinyl ester response in the triglyceride-rich plasma lipoprotein (TRL) fraction in volunteers after a single test meal with beta-carotene alone, or beta-carotene combined with lutein or lycopene. Results indicate an inhibitory effect of lutein on beta-carotene absorption, but apparently not on beta-carotene cleavage. In a comparative study with two beta-carotene/lutein ratios (2:1 and 1:2, respectively), this inhibitory effect of lutein was found to be most marked when lutein was the predominant carotenoid. In studies on plasma (serum) response also an inhibitory effect of beta-carotene on lutein response was observed.