Meal triacylglycerol profile modulates postprandial absorption of carotenoids in humans

Scope: Dietary lipids are considered to be primary potentiators of carotenoid absorption, yet the amount and source required to optimize bioavailability has not been systematically evaluated. The objective of this study was to examine the impact of both amount and source of triacylglycerols on postprandial absorption of carotenoids from vegetable salads. Methods and results: Healthy subjects (n = 29) were randomized using a Latin square design (3x3) and consumed three identical salads with 3, 8, or 20 g of canola oil, soybean oil, or butter. Blood was collected from 0-10 h and triacylglycerol-rich fractions (TRLs) were isolated by ultracentrifugation. Carotenoid contents of TRL fractions were analyzed by HPLC-DAD. Considering all lipid sources, 20 g of lipid promoted higher absorption compared to 3 and 8 g for all carotenoid species (p < 0.05), except for alpha-carotene (p = 0.07). The source of lipid had less impact on the absorption of carotenoids than amount of lipid. Pooling results from all lipid amounts, monounsaturated fatty acid rich canola oil trended toward enhancing absorption of lutein and alpha-carotene compared to saturated fatty acid rich butter (p = 0.06 and p = 0.08, respectively). Conclusion: While both amount and source of co-consumed lipid affect carotenoid bioavailability from vegetables, amount appears to exert a stronger effect.