The Association between Caffeine Intake and Testosterone: NHANES 2013-2014

Abstract Background Investigations into the link between caffeine consumption and testosterone levels in men have recently gained more attention, although studies are limited and the results are inconclusive. Methods Using data from a cross-sectional study of 372 adult men in the 2013-2014 NHANES survey cycle, we set out to characterize the association between serum testosterone levels, caffeine, and 14 caffeine metabolites. Results Multivariable, weighted linear regression revealed a significant inverse association between caffeine and testosterone. Multivariable linear regression revealed significant, inverse associations between 6 xanthine metabolic products of caffeine and testosterone. Inverse associations were observed between 5-methyluric acid products and testosterone, as well as between 5-acetlyamino-6-amino-3-methyluracil and testosterone. A significant, positive association was observed for 7-methyl xanthine, 3,7-dimethyluric acid, and 7-methyluric acid. Logistic regression models to characterize the association between 2 biologically active metabolites of caffeine (theobromine and theophylline) and odds of low testosterone (<300 ng/dL) were non-significant. Conclusions These findings suggest a potential role for caffeine’s contribution to low testosterone and biochemical androgen deficiency. Future studies are warranted to corroborate these findings, determine dose-response effects of caffeine on testosterone, and evaluate biological mechanisms underlying this association.