Objective:

To investigate the association between habitual coffee consumption and metabolic and hormonal profiles in middle-aged adults.

Approach:

• Study Design: A cross-sectional study analyzing data from 2264 participants in the Northern Finland Birth Cohort 1966, all aged 46 years.
• Data Collection: Combined reported coffee consumption with clinical measurements, hormone testing, and nuclear magnetic resonance metabolomics.
• Metabolomics Analysis: Quantified 164 lipid and metabolite measures to assess associations with coffee consumption.

Key Findings:

• Higher coffee consumption was associated with lower concentrations of branched-chain amino acids (BCAAs), which are linked to insulin resistance.
• Men showed lower fasting insulin and measures of insulin resistance with greater coffee intake, along with higher insulin sensitivity.
• Hormonal testing indicated higher total and bioavailable testosterone and SHBG in men, but lower free testosterone and free androgen index.
• Among women, associations were limited but showed higher SHBG and lower free testosterone.
• Higher coffee intake correlated with lower total and visceral fat and greater skeletal muscle mass.

Interpretation:

The study indicates that habitual coffee intake may be associated with variations in metabolic and endocrine biomarker profiles, with differences observed between sexes.

Limitations:

• Coffee intake was self-reported.
• Biomarkers were measured at a single time point.
• The Finnish cohort may not represent other populations with different coffee-drinking patterns.
• The findings do not establish causation.

Conclusion:

Longitudinal and intervention studies are needed to determine if the observed metabolic and hormonal changes can inform individual diagnostic or risk-assessment decisions.

Sources:

• The European Journal of Nutrition