The effects of caffeine administration on the early stage of bone healing and bone density A histometric study in rats

Objective: The aim of this study was to evaluate the effect of the daily administration of high doses of caffeine on the early stages of bone healing and on bone density in rats. Methods: Twenty-four Wistar rats were assigned to one of the following groups: Non-caffeine group (n = 12): animals without caffeine ingestion; Caffeine group (n = 12): 10 mg/100 g body weight/day of caffeine via drinking water for 56 days. Forty-eight days after the beginning of caffeine intake, a critical-size surgical defect was created in the right tibia of both groups, while the contralateral tibia was left without defect. Eight days later, the animals were sacrificed and the specimens processed in order to obtain decalcified sections. The area of new bone formation in the right tibia and the bone density in the left tibia were histometrically evaluated in the medular bone. Results: At 8 days post-operative, the caffeine group presented a significantly lower area of new bone formation, when compared to the non-caffeine group (p < 0.001). In addition, the administration of caffeine during 56 days did not alter the bone density. Conclusion: In conclusion, the present study demonstrated that a high daily caffeine intake may disturb the early stages of bone healing, but does not alter bone density after a period of 56 days of administration. (C) 2009 Elsevier Ltd. All rights reserved.