Effects of Regular Coffee Consumption on Serum C-Terminal Telopeptides Type I Collagen (CTx) and Calcium Levels in Female Young Adults

The adverse effect of coffee on bone metabolism is an unresolved controversy until now. Coffee was speculated as an enhancer of calcium loss and also a trigger for bone resorption. The purpose of this study was to analyze the effect of coffee consumption on bone resorption in female. Biomarker of bone resorption is a serum C-terminal Telopeptide Type I collagen (CTx). This study was a cross-sectional study. The subjects used in this study were female, aged 18-25 years, non-smokers, not taking calcium supplements, non-alcoholic drinker, non-coffee drinker and those that consume 1-2 cups of coffee a day, and healthy. A total of 65 volunteer participants were included in this study. CTx levels were measured by Electrochemical Luminescence Immunoassay (ECLIA). Calcium was examined using the Ortho Cresol Phthalein Complexone (CPC). We found that there was no significant difference in CTx levels between the non-coffee and coffee groups (0.561±0.28 vs 0.573±0.26; p=0.08). There were no significant differences in calcium between the non-coffee and coffee groups (9.40±0.42 vs 9.22±0.33; p=0.07). In conclusion, daily coffee consumption does not increase serum CTx levels nor does it reduces serum calcium levels. In this study therefore, coffee did not trigger an increase in bone resorption and calcium loss. Consumption of 1-2 cups of coffee (150-200 ml) or 2 times daily could maintain normal calcium levels in the body without adverse effects on the bone