Relationship of tea consumption and its circulating biomarkers with longitudinal bone mineral changes: a prospective cohort study with repeated measurements.

BACKGROUND

Tea is a dietary source of flavan-3-ols, which may influence bone health, but prospective evidence linking tea intake and its circulating biomarkers with longitudinal bone mineral status remains limited.

OBJECTIVES

To examine associations of tea consumption and its serum biomarkers with bone mineral status in Guangzhou Nutrition and Health Study.

METHODS

In 1708 participants, whole-body, total hip, lumbar spine, and femoral neck bone mineral density (BMD) and bone mineral content (BMC) were measured using dual-energy X-ray absorptiometry at 4 repeated visits during a 13-y follow-up period. Baseline serum flavan-3-ols, including epicatechin, epigallocatechin gallate (EGCG), epicatechin gallate (ECG), epigallocatechin, and catechin, were quantified using ultra-high-performance liquid chromatography-tandem mass spectrometry. Tea consumption was categorized as non-, low-, moderate-, or high-frequency. Multivariable linear mixed-effects models, including exposure × visit interactions, were used to evaluate visit-averaged bone mineral measures and longitudinal trajectories.

RESULTS

Among 1708 participants, significant tea consumption group × visit interactions were observed for whole-body, lumbar spine, and femoral neck BMD and whole-body BMC (P-interaction ranged from <0.001 to 0.022). Moderate-frequency tea drinkers generally had the highest visit-averaged adjusted marginal mean Z-scores, including 0.107 (95% CI: 0.025, 0.190) for whole-body BMD, 0.090 (0.012, 0.168) for lumbar spine BMD, and 0.108 (0.029, 0.187) for femoral neck BMD (P-diff ranged from <0.001 to 0.017). In analyses of serum tea biomarkers, higher biomarker categories were generally associated with more favorable bone mineral measures; however, the associations were not consistently linear, and several biomarkers showed nonmonotonic patterns. Visit-averaged differences were most extensive across ECG and EGCG categories.

CONCLUSIONS

Moderate-frequency tea consumption and higher categories of selected circulating tea biomarkers were associated with more favorable bone mineral status.