Research
Coffee consumption and CYP1A2 genotype in relation to bone mineral density of the proximal femur in elderly men and women: a cohort study
-
* Corresponding author: Helena Hallström heha@slv.se
1 Research and Development Department, Toxicology Division, National Food Administration, Box 622, SE-751 26 Uppsala, Sweden
2 Uppsala Clinical Research Center (UCR), University Hospital, SE-751 85 Uppsala, Sweden
3 Department of Medical Sciences, Section of Clinical Pharmacology, Uppsala University, SE-751 85 Uppsala, Sweden
4 Department of Medical Sciences, Section of Acute and Internal Medicine, Uppsala University, SE-751 85 Uppsala, Sweden
5 Department of Medical Sciences, Molecular Medicine, Uppsala University, SE-751 85 Uppsala, Sweden
6 Department of Surgical Sciences, Section of Orthopedics, Uppsala University, SE-751 85 Uppsala, Sweden
Nutrition & Metabolism 2010, 7:12 doi:10.1186/1743-7075-7-12
Published: 22 February 2010Abstract
Background
Drinking coffee has been linked to reduced calcium conservation, but it is less clear whether it leads to sustained bone mineral loss and if individual predisposition for caffeine metabolism might be important in this context. Therefore, the relation between consumption of coffee and bone mineral density (BMD) at the proximal femur in men and women was studied, taking into account, for the first time, genotypes for cytochrome P450 1A2 (CYP1A2) associated with metabolism of caffeine.
Methods
Dietary intakes of 359 men and 358 women (aged 72 years), participants of the Prospective Investigation of the Vasculature in Uppsala Seniors (PIVUS), were assessed by a 7-day food diary. Two years later, BMD for total proximal femur, femoral neck and trochanteric regions of the proximal femur were measured by Dual-energy X-ray absorptiometry (DXA). Genotypes of CYP1A2 were determined. Adjusted means of BMD for each category of coffee consumption were calculated.
Results
Men consuming 4 cups of coffee or more per day had 4% lower BMD at the proximal femur (p = 0.04) compared with low or non-consumers of coffee. This difference was not observed in women. In high consumers of coffee, those with rapid metabolism of caffeine (C/C genotype) had lower BMD at the femoral neck (p = 0.01) and at the trochanter (p = 0.03) than slow metabolizers (T/T and C/T genotypes). Calcium intake did not modify the relation between coffee and BMD.
Conclusion
High consumption of coffee seems to contribute to a reduction in BMD of the proximal femur in elderly men, but not in women. BMD was lower in high consumers of coffee with rapid metabolism of caffeine, suggesting that rapid metabolizers of caffeine may constitute a risk group for bone loss induced by coffee.