Several bioactive metabolites found in coffee may be associated with a beneficial effect on bone mineral density among healthy adults who report regular coffee consumption, according to findings published in The Journal of Clinical Endocrinology & Metabolism.
“It is widely known that coffee contains caffeine, which has been shown to adversely affect bone health by accelerating calcium loss or reducing calcium absorption,” Ching-Lung Cheung, PhD, assistant professor in the department of pharmacology and pharmacy at the University of Hong Kong, told Healio. “Despite the well-reported adverse effect of caffeine on bone health, contradictory findings were often observed between coffee consumption and BMD in published studies. Our large-scale epidemiology study involving approximately 7,000 participants from the Hong Kong Osteoporosis Study showed that coffee consumption was associated with higher BMD, after accounting for major confounding factors. Using a metabolomics approach, we further showed that a few bioactive compounds in coffee may be responsible for the positive association between coffee consumption and BMD.”
Cheung and colleagues analyzed data from 564 healthy Chinese adults participating in the Hong Kong Osteoporosis Study, a prospective cohort study initiated in 1995 to investigate the incidence of osteoporosis (81.2% women; 91.8% nonsmokers). Participants were recruited between 2001 and 2010 (cohort 1; n = 329) and in-person follow-up visits occurred between 2015 and 2016 (cohort 2; n = 235). For both visits, participants self-reported coffee consumption via a food frequency questionnaire; participants reported how frequently they consumed coffee during the past year and on average how many cups (at 250 mL per cup) were consumed each time. Researchers conducted untargeted metabolomic profiling with fasting serum samples using liquid chromatography-mass spectrometry. BMD at the lumbar spine and femoral neck was measured via DXA. Researchers used linear regression and robust regression analyses to investigate the association between coffee consumption and BMD parameters.
For both cohorts, 42.4% of participants reported not drinking coffee and 14.4% reported consuming more than one cup of coffee each day.
Several bioactive metabolites found in coffee may be associated with a beneficial effect on bone mineral density among healthy adults who report regular coffee consumption.
The researchers found that 12 serum metabolites were positively correlated with coffee consumption, with 5-acetylamino-6-formylamino-3-methyluracil (AFMU), quinate, 3-hydroxypyridine sulfate, and trigonelline (N-methylnicotinate) showing the strongest association. Among these metabolites, 11 were previously associated with coffee intake and six were related to caffeine metabolism, according to the researchers.
The metabolite AFMU was associated with BMD at the lumbar spine (P = .013), whereas 3-hydroxyhippurate (P = .027) and trigonelline (P = .043) were associated with BMD at the femoral neck.
Among 453 participants with metabolomics data assessed at baseline and follow-up (median follow-up time, 10.3 years), 11 experienced a hip fracture after assessment (seven women). In Cox regression analysis adjusted for age, sex, weight, height, smoking status and fracture history, higher coffee consumption was associated with reduced fracture risk; however, results were not statistically significant.
The researchers noted that the inverse yet insignificant association observed between coffee consumption and hip fracture risk may be explained by the small effect size of coffee consumption on BMD improvement and the multifactorial nature of hip fracture.
“Although we believe that more studies should be done in this area, our message is that coffee consumption is not necessarily linked to osteoporosis, and it may even be associated with better bone health,” Cheung said. “In this study, we identified a few metabolites that are associated with increased BMD. It would be interesting to investigate if these metabolites are causally associated with BMD. Such investigation may lead to the development of a novel dietary supplement for improving bone mass.” – by Regina Schaffer
For more information:
Ching-Lung Cheung, PhD, can be reached at the University of Hong Kong, Department of Pharmacology and Pharmacy, 21 Sassoon Road, Pokfulam, Hong Kong; email: firstname.lastname@example.org.
Disclosures: The authors report no relevant financial disclosures.