Effects of Caffeine on the Bones of Aged, Ovariectomized Rats

Abstract

Caffeine is a substance which many people consume in their daily life. Caffeine’s effects on bone are still controversial. Using ovariectomized rats, the present study was conducted to determine to what extent caffeine intake affects the mechanical properties, bone minerals and histology. Aged rats were divided into 2 groups after ovariectomy. Group 1 was fed a 20% protein diet as a control, and group 2 was fed a 20% protein diet supplemented with caffeine (2 mg/100 g body weight). The respective diets were fed to the rats of each group for 90 days. Rats were then killed by heart puncture, blood was collected, and femurs were removed. In 1 group of femurs paraffin cross-sections were made at the midshaft of each bone. Total width, cortical width, total cross-sectional bone area of the midshaft, and the number of osteocytes in randomly selected areas were measured. Another group of bones was subjected to three-point bending testing until failure. Bones were then pulverized and Ca, P, Mg, Zn, Sr, Si, hydroxyproline and hexosamine contents and crystallite size were measured. Various mechanical properties, except modulus of elasticity, in the caffeine group were consistently 7–23% lower than the noncaffeine controls. Yield strain in the caffeine group was significantly less than in the noncaffeine controls. Zinc, Sr, and crystallite size of bone showed a significant decrease in the caffeine group, whereas Si contents significantly increased. Our current results indicate that routine intake of caffeine in the elderly should be regarded with some caution.

Favorable effect of moderate dose caffeine on the skeletal system in ovariectomized rats

“…Based on the studies on calcium balance, and 1,25(OH) 2 D 3 , and PTH levels, Yeh et al proposed that older rats may be more vulnerable to deleterious caffeine effects since they are less able to increase calcium absorption in response to the increased excretion. Consistently with this notion, that mechanism might have been activated in ovariectomized rats much older than those used in our experiment, treated with the same moderate dose of caffeine (in the diet), in which not only the lack of favorable effect, but a tendency to damage the bone was observed .…”

A Caffeine Diet Can Alter the Mechanical Properties of the Bones of Young Ovariectomized Rats

“…In contrast to a previous study [39], in which caffeine's effects on the mechanical properties of bone of aged, ovariectomized rats were studied, in the present study, we have studied the effects of caffeine on the mechanical properties of growing bones in early life. This is the first demonstration of an impairment of the mechanical properties of the growing bones as a result of caffeine exposure in early life.…”

Cola beverage consumption delays alveolar bone healing: a histometric study in rats

“…9,15 Furthermore, cola beverages are rich in caffeine, which has been associated with reduced bone mineral density and increased fracture risk. 16,17 According to Kinney 18 (2002), non-cola carbonated soft drinks, which do not contain phosphoric acid or caffeine, have not been associated with fracture risk among Graph 1 -Neoformed bone trabeculae (%) (mean ± SEM) in the alveolar apical third of rats from the control and cola groups at two and three weeks after tooth extraction (one way ANOVA followed by Tukey's multiple comparison test, *statistically significant difference between the cola group and respective control, p < 0.01). children and adolescents.…”