SGEM#509: I love the Java Jive & It Loves Me – Preventing Dementia with Coffee and Tea

Date: April 23, 2026  Guest Skeptic: Dr. Manrique Umaña McDermott is an attending physician specializing in Emergency Medicine based in San José, Costa Rica. He has a passion for medical education, is a renowned international speaker and serves as a faculty member in undergraduate Internal Medicine at UCIMED and postgraduate training programs in Emergency Medicine and Family and Community Medicine at the University of Costa Rica (UCR). You can follow him on X and Instagram at @umanamd.  Reference: Zhang et al. Coffee and Tea Intake, Dementia Risk, and Cognitive Function. JAMA 2026 March Case: A 47-year-old emergency physician presents to their primary care physician for a rare act of preventive care between a run of night shifts. She drinks 3 large coffees most workdays, switches to tea on post-nights when her hands are vibrating fast enough to start an IV at 20 paces and asks whether her caffeine habit is frying her brain or secretly protecting it. She has heard that coffee is either a miracle, a menace, or both, depending on which headline got posted in the group chat that week. Background: Coffee’s origin story reads like a case report from the annals of caffeinated discovery. Legend traces it back to Ethiopia, where a goat herder observed his animals behaving like over-caffeinated residents after nibbling on certain berries. From there, coffee spread through the Arabian Peninsula, where it was first cultivated and consumed in Yemen, eventually fueling the rise of coffeehouses. By the 17th century, coffee had reached Europe, where it was alternately praised as a miracle tonic and condemned as a suspicious stimulant. Over time, coffee became embedded in global culture, transitioning from a mystical brew to an industrial-scale commodity, and ultimately, a critical adjunct in emergency medicine workflow optimization. Costa Rica takes coffee seriously, arguably more seriously than most emergency departments (EDs) take shift coffee orders. Introduced in the late 18th century, coffee quickly became a cornerstone of the country’s economy and identity. The government actively promoted coffee cultivation, even offering farmers free land to grow it, resulting in a thriving industry based on small family farms rather than large plantations. Costa Rican coffee is renowned for its high quality, thanks to ideal growing conditions: volcanic soil, high altitude, and just enough rain to keep things interesting. The country even banned the production of low-quality coffee. Today, Costa Rica is a leader in sustainable coffee production. So, the next time you’re powering through a night shift, there’s a good chance your cognitive performance is being supported by carefully cultivated beans from a hillside in Central America. Emergency physicians do not need a pathophysiology lecture on caffeine; they need a fresh cup. Coffee is practically a staffing model, while tea is the civilized cousin, and both have long been part of the informal pharmacopeia of night shift survival. The real question is whether our specialty’s favourite legal liquid stimulant does anything beyond keeping our differential diagnoses alive until sunrise. Biologically, the hypothesis is plausible. Coffee and tea contain caffeine and other bioactive compounds, including polyphenols, that may influence oxidative stress, neuroinflammation, vascular function, and insulin sensitivity. These are all pathways that could plausibly matter for cognitive decline and dementia. But human studies have been inconsistent, and many older studies did not clearly distinguish between caffeinated and decaffeinated coffee.  Clinical Question: Is long-term intake of caffeinated coffee, decaffeinated coffee, or tea associated with incident dementia and cognitive outcomes? Reference: Zhang et al. Coffee and Tea Intake, Dementia Risk, and Cognitive Function. JAMA 2026 March Population: Adults from the Nurses’ Health Study (NHS) and Health Professionals Follow-up Study (HPFS). Excluded: People with cancer, Parkinson’s disease, or dementia at baseline; those with implausible total energy intake; and those missing caffeinated beverage intake data.  Exposure: Long-term intake of caffeinated coffee, decaffeinated coffee, and tea, assessed every 2 to 4 years with validated food frequency questionnaires (FFQs).  Comparison: Lower intake categories, especially the lowest quartile or tertile of consumption, depending on the beverage.  Outcomes: Primary Outcome: Incident dementia, identified via death records and physician diagnoses.  Secondary outcomes: Subjective cognitive decline and objective cognitive function; objective testing was assessed only in the NHS cohort, including a telephone interview for cognitive status (TICS) and composite cognitive measures.  Type of Study: Prospective observational cohort study. Authors’ Conclusions: “Greater consumption of caffeinated coffee and tea was associated with lower risk of de