The influence of food matrices on the bioavailability of curcuminoids from a dried colloidal turmeric suspension: a randomized, crossover, clinical trial†

Curcuminoid absorption can be influenced by the presence of additional compounds, but there has been no study investigating this in a robust manner. The aim of this clinical trial was to assess the effect of the type of food matrix on the absorption of curcuminoids from a highly bioavailable turmeric formulation. Participants consumed the turmeric formulation in the form of capsules, a ready-to-drink fruit nectar, a sports nutrition bar, a dairy analogue (oat milk), pectin gummies, and a probiotic drink in a randomized, crossover study. Plasma samples were collected over a 24-hour period to assess the pharmacokinetics of curcuminoids. The relative bioavailability of total curcuminoids was increased in all the food matrices compared to that in the capsule formulation. The dairy analogue showed the highest increase in dose-normalized AUC_{24 h} (+76%, p < 0.0001) and C_max (+105%, p < 0.0001). The sports nutrition bar resulted in increased dose-normalized AUC_{24 h} (+40%, p = 0.0112) and C_max (+74%, p < 0.0001). The probiotic drink showed increased dose-normalized AUC_{24 h} (+35%, p = 0.0318) and C_max (+52%, p < 0.0001). The ready-to-drink and gummy formulations were bioequivalent to the capsules. The distribution of curcuminoid metabolites was similar in all the matrices. In conclusion, there was no negative food matrix effect; on the contrary, the bioavailability of curcuminoids can be improved when administered via food matrices, particularly those containing lipids in a suspended form or polar lipids.