Absorption and urinary excretion of the coffee diterpenes cafestol and kahweol in healthy ileostomy volunteers

Abstract

de Roos B, Meyboom S, Kosmeijer-Schuil TG, Katan MB (Wageningen). Absorption and uri-nary excretion of the coffee diterpenes cafestol and kahweol in healthy ileostomy volunteers. J Intern Med 1998; 244: 451-60. Objectives. To determine the absorption and urinary excretion of the cholesterol-raising coffee diterpenes cafestol and kahweol in humans. Subjects and design. Nine healthy ileostomists consumed a dose of one, two or three cups of French-press coffee together with a standardized breakfast on three separate days in random order. Subsequently, ileostomy effluent was collected for 14 h and urine for 24 h. Stability of cafestol and kahweol was also assessed under simulated gastro-intestinal tract conditions. Main outcome measures. Absorption of diterpenes, stability of diterpenes during incubation with gastrointestinal fluids, and urinary excretion of diterpenes. Results. Corrected mean absorptions expressed as percentages of the amount consumed and the amount entering the duodenum were 67 and 88%, respectively, for cafestol, and 72 and 93%, respectively , for kahweol. We found losses of diterpenes during incubation in vitro with gastric juice (cafestol, 24%; kahweol, 32%), during storage with ileostomy effluent (cafestol, 18%; kahweol, 12%), and during freeze-drying (cafestol, 26%; kahweol, 32%). Mean excretion of glucuronidated plus sulphated conjugates in urine was 1.2% of the ingested amount for cafestol and 0.4% of the ingested amount for kahweol. Conclusions. About 70% of the ingested cafestol and kahweol is absorbed in ileostomy volunteers. Possibly, undetected metabolites are present in ileostomy effluent , resulting in lower absorption percentages. Only a small part of the diterpenes is excreted as a conjugate of glucuronic acid or sulphate in urine. Therefore, these compounds are extensively metabolized in the human body.

New Biomarkers of Coffee Consumption Identified by the Non-Targeted Metabolomic Profiling of Cohort Study Subjects

“…The metabolism of cafestol and kahweol in humans is poorly documented. An intervention study in ileostomy volunteers showed that both are well absorbed in the small intestine but little is excreted as conjugates of glucuronic acid or sulfate in urine, suggesting other metabolic routes such as oxidation [30]. Oxidation of the primary alcohol of kahweol with subsequent glucuronidation of this alcohol was the first biotransformation predicted by Meteor software, supporting our tentative identification.…”

The Pocket-4-Life project, bioavailability and beneficial properties of the bioactive compounds of espresso coffee and cocoa-based confectionery containing coffee: study protocol for a randomized cross-over trial

“…Nevertheless, despite substantial research on caffeine, trigonelline, and phenolic compounds [ 33 ], there is a lack of fundamental knowledge on this critical topic, even more when it comes to different patterns of consumption including the number of daily servings and repeated daily doses, which represents a common scenario among coffee consumers. In addition, the circulating metabolites derived from coffee diterpenes [ 35 , 68 , 69 ], potent cholesterol-raising compounds, are still unknown. This information is paramount to draw a more realistic physiological picture and, hence, to better understand the biological properties of long-term coffee consumption [ 33 , 61 ].…”

Melatonin sensitizes Caki renal cancer cells to kahweol‐induced apoptosis through CHOP‐mediated up‐regulation of PUMA

“…However, oral administration of melatonin via the drinking water was also reported to be effective in suppressing 7,12-dimethylbenzanthracene-induced mammary tumor growth [39]. In addition, for adults consuming moderate amounts of coffee (3-4 cups/day providing 300-400 mg/day of caffeine), there is little evidence of health risks and some evidence of health benefits [40]. A number of clinical and basic studies are required to establish the effects of melatonin on certain cancer.…”