Metabolomics of food intake and its association with osteoporosis

Abstract

Diet plays an important role in the maintenance of bone mass and prevention of osteoporosis and fracture. Milk and coffee are popular beverages that contain biochemicals that affect bone metabolism. Habitual intake of these beverages has been widely studied for their effect on bone health but findings are inconsistent. This could be attributed to the intrinsic limitation of memory-based dietary assessments used in previous studies. Recently, metabolomics has provided an objective means to identify diet-associated biomarkers, and is considered a complementary approach to traditional methods that estimate dietary exposure.

Currently, metabolomic study of dietary intake has been very limited in the Chinese population. Milk- and coffee-associated metabolites remain largely unidentified and their effect, if any, on bone health is unknown.

In this study, untargeted metabolomic profiling was performed on fasting serum samples obtained from a Southern Chinese cohort using liquid chromatography–mass spectrometry. Biomarkers of habitual dietary intake were identified by a multivariable linear regression model of a food frequency questionnaire. The association between these metabolites and bone mineral density at three skeletal sites was further examined by the robust regression model.

This study demonstrated that metabolomics is a powerful approach that can identify biomarkers of milk and coffee intake among Chinese. N-trimethyl 5-aminovalerate was the milk-associated metabolite that positively correlated with bone mineral density at the hip. Twelve coffee-associated metabolites were identified, of which three were positively correlated with bone mineral density at the lumbar spine and femoral neck, and could be potential biomarkers of milk and coffee intake that reflect bone health. Whether they are causally associated with bone health requires further study.