Comparison of the bioavailability of natural palm oil carotenoids and synthetic β-carotene in humans

Palm oil carotenoids are a mixture of α- and β-carotenes, which are used as food colorants. They may also be applied as a functional food ingredient because of the provitamin A activity of α- and β-carotenes and their proposed beneficial roles in the prevention of chronic diseases. This paper discusses the results of an incomplete balanced crossover study with 69 healthy adult volunteers to compare palm oil carotenoids with synthetic β-carotene in their efficacies to increase plasma levels of carotenoids. Four days of supplementation with natural palm oil carotenoids (7.6 mg/day of α-carotene, 11.9 mg/day of all-trans-β.-carotene, 7.5 mg/day of cis-β-carotene) or synthetic β-carotene (23.8 mg/day of all-trans-β-carotene, 4.4 mg/day of cis-β-carotene), added to a mixed meal, resulted in significant increases in plasma levels of the supplied carotenoids as compared to consumption of a low-carotenoid meal (i.e., 7.2-fold increase in α-carotene and 3.5-fold increase in all-trans-β-carotene following palm oil carotenoids; 6.9-fold increase in all-trans β-carotene following synthetic β-carotene). As the carotenoid content differed between the treatments, the relative plasma responses were calculated per milligram of β-carotene intake. These were similar for the two supplements, suggesting that the presence of α-carotene does not affect the bioavailability of β-carotene from palm oil. It was concluded that 4 days of supplementation with palm oil carotenoids or synthetic β-carotene improves the plasma β-carotene status substantially, whereas α-carotene is additionally delivered by the palm oil supplement.