U.S. Department of Agriculture, Agricultural Research Service. (2019). FoodData Central — Coffee, brewed, and caffeine component data. Brewed coffee ~95-200 mg caffeine per ~240 mL cup (roughly double brewed tea). fdc.nal.usda.gov
Poole, R., Kennedy, O. J., Roderick, P., Fallowfield, J. A., Hayes, P. C., & Parkes, J. (2017). Coffee consumption and health: umbrella review of meta-analyses of multiple health outcomes. BMJ, 359, j5024. ~3-4 cups/day vs none associated with lowest all-cause mortality (RR ~0.83) and lower cardiovascular mortality; benefit non-linear; observational. 10.1136/bmj.j5024
Institute of Medicine (US) Committee on Military Nutrition Research. (2001). Pharmacology of caffeine. In Caffeine for the Sustainment of Mental Task Performance. National Academies Press. Caffeine elimination half-life 4-5 h in healthy adults; >95% metabolized by hepatic CYP1A2; adenosine-receptor antagonism is the principal CNS mechanism. www.ncbi.nlm.nih.gov/books/NBK223808
Jacobson, K. A., et al. (2022). Adenosine receptor antagonists: from caffeine to selective non-xanthines. British Journal of Pharmacology, 179(15), 3496-3511. Caffeine acts as a pan-antagonist at human adenosine receptors, blocking A2A/A1-mediated sleepiness signaling. 10.1111/bph.15103
Ding, M., Bhupathiraju, S. N., Chen, M., van Dam, R. M., & Hu, F. B. (2014). Caffeinated and decaffeinated coffee consumption and risk of type 2 diabetes: a systematic review and a dose-response meta-analysis. Diabetes Care, 37(2), 569-586. 28 cohorts, >1.1 million participants; inverse dose-response (RR ~0.91 per cup/day); holds for decaffeinated coffee. 10.2337/dc13-1203
Loomis, D., Guyton, K. Z., Grosse, Y., et al. / IARC Monographs Vol. 116. (2016). Carcinogenicity of drinking coffee, mate, and very hot beverages. The Lancet Oncology, 17(7), 877-878. Coffee re-classified to Group 3 (not classifiable as to carcinogenicity); very hot beverages >65°C classified Group 2A (probably carcinogenic to the esophagus). 10.1016/S1470-2045(16)30239-X
Killer, S. C., Blannin, A. K., & Jeukendrup, A. E. (2014). No evidence of dehydration with moderate daily coffee intake: a counterbalanced cross-over study in a free-living population. PLoS ONE, 9(1), e84154. ~4 mg/kg/day caffeine via coffee vs water showed no difference in 24-h urine output or hydration markers in habitual drinkers. 10.1371/journal.pone.0084154
Cai, L., Ma, D., Zhang, Y., Liu, Z., & Wang, P. (2012). The effect of coffee consumption on serum lipids: a meta-analysis of randomized controlled trials. European Journal of Clinical Nutrition, 66(8), 872-877. 12 RCTs, 1,017 subjects; coffee (largely unfiltered, cafestol-containing) raised total cholesterol ~8 mg/dL, LDL ~5 mg/dL, triglycerides ~13 mg/dL; filtered coffee produced essentially no rise. 10.1038/ejcn.2012.68
American College of Obstetricians and Gynecologists Committee on Obstetric Practice. (2010, reaffirmed). Committee Opinion No. 462: Moderate caffeine consumption during pregnancy. Obstetrics & Gynecology, 116(2 Pt 1), 467-468. Recommends limiting caffeine to <200 mg/day in pregnancy. 10.1097/AOG.0b013e3181eeb2a1
EFSA Panel on Dietetic Products, Nutrition and Allergies. (2015). Scientific opinion on the safety of caffeine. EFSA Journal, 13(5), 4102. Abstract: single doses up to 200 mg (about 3 mg/kg bw for a 70-kg adult) and habitual intake up to 400 mg per day raise no safety concerns for non-pregnant adults; up to 200 mg per day in pregnancy raises no concern for the fetus; single doses and habitual intake up to 200 mg by lactating women raise no concern for breastfed infants; for children and adolescents the data were insufficient to derive a safe intake, and the Panel suggests the adult 3 mg/kg bw per day as a basis. Typical energy-drink constituents, and alcohol up to about 0.65 g/kg bw, would not affect the safety of single caffeine doses up to 200 mg (abstract, Wiley page via Wayback snapshot 8 January 2025). 10.2903/j.efsa.2015.4102
Drake, C., Roehrs, T., Shambroom, J., & Roth, T. (2013). Caffeine effects on sleep taken 0, 3 or 6 hours before going to bed. Journal of Clinical Sleep Medicine, 9(11), 1195-1200. Randomized, double-blind, placebo-controlled Latin-square crossover in 12 healthy normal sleepers: one fixed 400 mg dose of caffeine (the authors call it moderate) at 0, 3 or 6 h before habitual bedtime vs placebo, sleep measured at home by diary and a portable monitor. All three timings disrupted sleep vs placebo (P < 0.05). By the objective monitor, even at 6 h caffeine reduced sleep by more than 1 hour; by diary, the 6-h reduction in total sleep time (41 min) only approached significance (p = 0.08). The authors conclude that substantial caffeine should be avoided for a minimum of 6 hours before bedtime, and that afternoon caffeine should at least be restricted to before 17:00 (abstract, PMID 24235903; full text, PMC3805807). 10.5664/jcsm.3170
