Trial reportNutrition journal2012
The effects of caffeinated and decaffeinated coffee on sex hormone-binding globulin and endogenous sex hormone levels: a randomized controlled trial.
Trial report in Nutrition journal, 2012. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 16 papers, 3 of them syntheses that pooled it.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
16 citing papers in PubMed, 3 syntheses or guidelines pooled it, 48 citations in OpenAlex.
- The Relation between Caffeine Consumption and Endometriosis: An Updated Systematic Review and Meta-Analysis.Nutrients · 2021Pooled it
- Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes.BMJ (Clinical research ed.) · 2017Pooled it
- Coffee and caffeine intake and risk of endometriosis: a meta-analysis.European journal of nutrition · 2014Pooled it
- Coffee consumption and plasma biomarkers of metabolic and inflammatory pathways in US health professionals.The American journal of clinical nutrition · 2019Trial
- Lifestyle INtervention for Diabetes prevention After pregnancy (LINDA-Brasil): study protocol for a multicenter randomized controlled trial.BMC pregnancy and childbirth · 2016Trial
- Associations of habitual coffee intake with testosterone and cardiometabolic markers: the Northern Finland birth cohort 1966 study.European journal of nutrition · 2026Article
- The influence of unhealthy lifestyle on semen quality: results from a cross-sectional study and Mendelian randomization analysis.Annals of medicine and surgery (2012) · 2026Article
- Causal effect of coffee consumption on metabolic syndrome in Korean adults: a 2-sample Mendelian randomization study.Nutrition research and practice · 2025Article
- Impact of Coffee Intake on Measures of Wellbeing in Mice.Nutrients · 2024Article
- Association between Coffee Consumption and Polycystic Ovary Syndrome: An Exploratory Case-Control Study.Nutrients · 2024Article
- Overview of the Effect of Complementary Medicine on Treating or Mitigating the Risk of Endometriosis.Revista brasileira de ginecologia e obstetricia : revista da Federacao Brasileira das Sociedades de Ginecologia e Obstetricia · 2021Review
- GreenJournal of diabetes research · 2020Article
- Coffee or Tea? A prospective cohort study on the associations of coffee and tea intake with overall and cause-specific mortality in men versus women.European journal of epidemiology · 2018Article
- Dose- and time-related effects of caffeine on the testis in immature male rats.Experimental animals · 2017Article
- Self-management and psychological-sexological interventions in patients with endometriosis: strategies, outcomes, and integration into clinical care.International journal of women's health · 2017Review
- Caffeine and saliva steroids in young healthy recreationally trained women: impact of regular caffeine intake.Endocrine · 2016Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 5 institutions in 2 countries.
Funding
Abstract
backgroundFindings from observational studies suggest that sex hormone-binding globulin (SHBG) and endogenous sex hormones may be mediators of the putative relation between coffee consumption and lower risk of type 2 diabetes. The objective of this study was to evaluate the effects of caffeinated and decaffeinated coffee on SHBG and sex hormone levels.
findingsAfter a two-week run-in phase with caffeine abstention, we conducted an 8-week parallel-arm randomized controlled trial. Healthy adults (n = 42) were recruited from the Boston community who were regular coffee consumers, nonsmokers, and overweight. Participants were randomized to five 6-ounce cups of caffeinated or decaffeinated instant coffee or water (control group) per day consumed with each meal, mid-morning, and mid-afternoon. The main outcome measures were SHBG and sex hormones [i.e., testosterone, estradiol, dehydroepiandrosterone sulfate]. No significant differences were found between treatment groups for any of the studied outcomes at week 8. At 4 weeks, decaffeinated coffee was associated with a borderline significant increase in SHBG in women, but not in men. At week 4, we also observed several differences in hormone concentrations between the treatment groups. Among men, consumption of caffeinated coffee increased total testosterone and decreased total and free estradiol. Among women, decaffeinated coffee decreased total and free testosterone and caffeinated coffee decreased total testosterone.
conclusionsOur data do not indicate a consistent effect of caffeinated coffee consumption on SHBG in men or women, however results should be interpreted with caution given the small sample size. This is the first randomized trial investigating the effects of caffeinated and decaffeinated coffee on SHBG and sex hormones and our findings necessitate further examination in a larger intervention trial.
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Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.