title: Absorption and urinary excretion of the coffee diterpenes cafestol and kahweol in healthy ileostomy volunteers.
abstract: OBJECTIVE
  To determine the absorption and urinary excretion of the cholesterol-raising coffee diterpenes cafestol and kahweol in humans.
  
  
  METHODS
  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 gastrointestinal tract conditions.
  
  
  METHODS
  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.
authors.affiliation: Division of Human Nutrition and Epidemiology, Wageningen Agricultural University, Wageningen, The Netherlands.
authors.forename: B
authors.initials: B
authors.lastname: De Roos
authors.forename: S
authors.initials: S
authors.lastname: Meyboom
authors.forename: T G
authors.initials: TG
authors.lastname: Kosmeijer-Schuil
authors.forename: M B
authors.initials: MB
authors.lastname: Katan
mesh_terms: D000328:Adult; D000368:Aged; D003069:Coffee / Q000378:metabolism; D004224:Diterpenes / Q000493:pharmacokinetics* / Q000652:urine; D004355:Drug Stability; D004386:Duodenum / Q000378:metabolism; D005260:Female; D006801:Humans; D007081:Ileostomy; D007408:Intestinal Absorption / Q000502:physiology*; D008297:Male; D008875:Middle Aged; D011897:Random Allocation
chemical_list: D003069:Coffee; D004224:Diterpenes; C053401:kahweol; C053400:cafestol