1–4 cups a day for most people; avoid caffeine in the afternoon if it affects your sleep.
Study in 411 older adults without dementia with brain PET: higher coffee consumption was associated with less amyloid deposition in the brain (a hallmark of Alzheimer's). Observational, cross-sectional association: it suggests protection, but does not prove it.
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Coffee is the most consumed beverage in the world after water and one of the most researched in the health sciences, and what decades of accumulated epidemiological and mechanistic research reveal is that it is not only not harmful in moderate consumption, but actively beneficial for a spectrum of conditions that includes cardiovascular disease, type 2 diabetes, cancer, neurodegenerative diseases, and biological aging; a study published in 2024 found that consuming one to three cups daily was associated with a 0.13-year reduction in the epigenetic marker PhenoAge, and more than three cups with a 0.16-year reduction, suggesting that coffee not only slows but actively reprograms gene expression toward younger patterns.
The chemical composition of coffee is extraordinarily complex: it contains more than 1,000 bioactive compounds, the most relevant being chlorogenic acids, which are polyphenols with potent antioxidant activity; the diterpenes cafestol and kahweol, which have paradoxical effects on cholesterol and cancer depending on the preparation method; caffeine, which acts on adenosine receptors in the brain; trigonelline, a precursor of niacin; and a wide variety of melanoidins and other compounds generated during the roasting process that have prebiotic activity on the gut microbiome.
The neuroprotective effects of coffee are especially robust for Parkinson's disease and dementia: studies in the UK Biobank cohort with nearly half a million participants found that consuming two to three cups of caffeinated coffee daily was associated with significant reductions in the incidence of Parkinson's disease and dementia, whereas decaffeinated coffee did not show these effects, which points to caffeine as the main neuroprotective component for these conditions; the most plausible mechanism is blockade of A2A adenosine receptors, which under normal conditions inhibit dopaminergic activity in the basal ganglia and whose overactivation is characteristic of Parkinson's disease.
One of the most practical findings of recent research on coffee is that the preparation method has relevant consequences for cardiovascular health: the diterpenes cafestol and kahweol, present in high concentration in coffee prepared with a French press, espresso, or Turkish coffee, can raise LDL cholesterol by 10 to 30 mg/dL with regular consumption; in contrast, paper filtering retains the diterpenes and allows the beneficial polyphenols to pass freely into the liquid, making filter coffee the preferred option from a cardiovascular standpoint; in addition, medium roasts preserve the concentration of antioxidants better than dark ones, where prolonged heat degrades chlorogenic acids.
A study published in 2025 with more than 40,000 individuals showed that coffee drinkers who concentrated their intake exclusively in the morning had all-cause mortality 16 to 29 percent lower than non-drinkers, and cardiovascular mortality 30 to 48 percent lower, whereas those who drank coffee throughout the day showed no reduction in mortality at any dose; the most likely mechanistic explanation is that caffeine taken in the afternoon or evening interferes with melatonin production and shifts the circadian clock, creating a state of chronic circadian misalignment that cancels out the benefits of coffee on longevity.
Information, not medical advice. Scientific evidence reflects the quality of the studies.