Breakfast consumption induces retarded release of chlorogenic acid metabolites in humans

Coffee is the main source of chlorogenic acids (CGAs) in human nutrition. In this study, one main point of interest was whether the simultaneous consumption of coffee and food affects the absorption and bioavailability of CGAs. Fourteen healthy participants consumed pure instant coffee (T1), or coffee with either a high-carbohydrate (T2) or a high-fat meal (T3). All volunteers consumed the same quantity of CGAs (3.1 mg CGA/kg bw), and blood and urine samples were collected at various time points for up to 15 h and 24 h after consumption, respectively. Existing CGAs, and their respective metabolite concentrations, were determined using HPLC–ESI-MS/MS. The area under the curve (AUC) was the measure of CGA quantity in plasma samples collected after each treatment. We observed significantly greater CGA bioavailability after pure instant coffee consumption (T1) than with an additional consumption of a high-fat meal (T3). However, the difference in CGA bioavailability between pure coffee (T1) and coffee plus high-carbohydrate meal (T2) was not statistically significant. The latter observation held true when T3-samples were compared with T2-samples. When the metabolites were split into their respective classes, significant differences in the sums of AUC were observed only for some classes, and not among the treatments. Data did not show differences in the total bioavailability, but revealed differences in the kinetic of release. The co-ingestion of breakfast favored a slow and continuous release of colonic metabolites in contrast to the non-metabolized coffee components appearing in the first hour after coffee consumption. Urine samples collected over 24 h did not show any statistically significant differences among the treatments. Only samples collected within the first 6 h post-coffee consumption showed that the CGA quantities in urine samples collected after T1 and T3 were significantly greater than quantities with an additional consumption of carbohydrates (T2). Breakfast had no significant effect on CGA absorption from coffee. However, a shift in gastrointestinal transit time and in the plasma metabolite composition was observed. So breakfast consumption induces retarded release of chlorogenic acid metabolites in humans.