June 15, 2015
J S Sisti et al, 2015, Caffeine, coffee and tea intake and urinary estrogens and estrogen metabolites in premenopausal women, Cancer Epidemiology Biomarkers and Prevention, published online ahead of print.
BACKGROUND: Prior studies have found weak inverse associations between breast cancer and caffeine and coffee intake, possibly mediated through their effects on sex hormones.
METHODS: High-performance liquid chromatography/tandem mass spectrometry was used to quantify levels of 15 individual estrogens and estrogen metabolites (EM) among 587 premenopausal women in the Nurses’ Health Study II with mid-luteal phase urine samples and caffeine, coffee and/or tea intakes from self-reported food frequency questionnaires. Multivariate linear mixed models were used to estimate geometric means of individual EM, pathways and ratios by intake categories, and P-values for tests of linear trend.
RESULTS: Compared to women in the lowest quartile of caffeine consumption, those in the top quartile had higher urinary concentrations of 16α-hydroxyestrone (28% difference; P-trend=0.01) and 16-epiestriol (13% difference; P-trend=0.04), and a decreased parent estrogens/2-, 4-, 16-pathway ratio (P-trend=0.03). Coffee intake was associated with higher 2-catechols, including 2-hydroxyestradiol (57% difference, ≥4 cups/day vs. ≤6 cups/week; P-trend=0.001) and 2-hydroxyestrone (52% difference; P-trend=0.001), and several ratio measures. Decaffeinated coffee was not associated with 2-pathway metabolism, but women in the highest (vs. lowest) category of intake (≥2 cups/day vs. ≤1-3 cups/month) had significantly lower levels of two 16-pathway metabolites, estriol (25% difference; P-trend=0.01) and 17-epiestriol (48% difference; Ptrend=0.0004). Tea intake was positively associated with 17-epiestriol (52% difference; Ptrend=0.01).
CONCLUSION: Caffeine and coffee intake were both associated with profiles of estrogen metabolism in premenopausal women.
IMPACT: Consumption of caffeine and coffee may alter patterns of premenopausal estrogen metabolism.
Ja tak, jeg vil gerne modtage nyhedsbrev, når der er noget nyt om kaffe og helbred.