title: Favorable effect of moderate dose caffeine on the skeletal system in ovariectomized rats.
abstract: METHODS
  Caffeine, a methylxanthine present in coffee, has been postulated to be responsible for an increased risk of osteoporosis in coffee drinkers; however, the data are inconsistent. The aim of the present study was to investigate the effects of a moderate dose of caffeine on the skeletal system of rats with normal and decreased estrogen level (developing osteoporosis due to estrogen deficiency).
  
  
  RESULTS
  The experiments were carried out on mature nonovariectomized and ovariectomized Wistar rats, divided into control rats and rats receiving caffeine once daily, 20 mg/kg p.o., for 4 wk. Serum bone turnover markers, bone mass, mass of bone mineral, calcium and phosphorus content, histomorphometric parameters, and bone mechanical properties were examined. Caffeine favorably affected the skeletal system of ovariectomized rats, slightly inhibiting the development of bone changes induced by estrogen deficiency (increasing bone mineralization, and improving the strength and structure of cancellous bone). Moreover, it favorably affected mechanical properties of compact bone. There were no significant effects of caffeine in rats with normal estrogen levels.
  
  
  CONCLUSIONS
  In conclusion, results of the present study indicate that low-to-moderate caffeine intake may exert some beneficial effects on the skeletal system of mature organisms.
authors.affiliation: Department of Pharmacology, Medical University of Silesia, Katowice, Poland.
authors.forename: Joanna
authors.initials: J
authors.lastname: Folwarczna
authors.forename: Maria
authors.initials: M
authors.lastname: Pytlik
authors.forename: Maria
authors.initials: M
authors.lastname: Zych
authors.forename: Urszula
authors.initials: U
authors.lastname: Cegieła
authors.forename: Ilona
authors.initials: I
authors.lastname: Kaczmarczyk-Sedlak
authors.forename: Barbara
authors.initials: B
authors.lastname: Nowińska
authors.forename: Leszek
authors.initials: L
authors.lastname: Sliwiński
mesh_terms: D000818:Animals; D015519:Bone Density / Q000187:drug effects*; D002110:Caffeine / Q000008:administration & dosage* / Q000009:adverse effects*; D002113:Calcification, Physiologic / Q000187:drug effects*; D002118:Calcium / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D004305:Dose-Response Relationship, Drug; D004967:Estrogens / Q000097:blood / Q000172:deficiency; D005260:Female; D010024:Osteoporosis / Q000473:pathology; D010052:Ovariectomy; D051381:Rats; D017208:Rats, Wistar; D015430:Weight Gain / Q000187:drug effects
chemical_list: D004967:Estrogens; D002110:Caffeine; D002784:Cholesterol; D002118:Calcium
keywords: Bone mechanical properties; Caffeine; Osteoporosis; Rats; Skeletal system