09/10/2025
Who Should Avoid Coffee?
Michael Greger M.D. FACLM · September 8, 2025 · Volume 70
There are certain medical conditions that are worsened by coffee intake.
Despite the plethora of health-promoting benefits associated with drinking coffee, including a longer life, could there be any “grounds for concern?” I’ve previously highlighted how coffee is not for everyone. People with glaucoma or perhaps even merely a family history of the eye disease may want to stay away from caffeinated coffee, as it can increase pressure in the eye, and exacerbate or contribute to glaucoma. There are case reports of individuals with epilepsy having dramatic decreases in the frequency of seizures after stopping coffee, so avoiding it or limiting yourself to no more than two and a half cups (600 ml) is certainly worth a try if you have a seizure disorder. Coffee may also worsen acid reflux disease.
U.S. and European guidelines for women both suggest reducing caffeine intake to reduce symptoms of urinary urgency and frequency. This makes sense. Caffeine is a mild diuretic, especially at doses found in more than two or three cups (480 or 720 ml) of coffee, though daily consumers may habituate and be less impacted. Surprisingly, though, a meta-analysis of observational studies found no evidence of a link between urinary incontinence and coffee intake, or caffeine more generally. In interventional studies of caffeine reduction, half found a decrease in urinary frequency, but for urinary incontinence, only two studies out of seven found a significant benefit. Again, though, what’s the harm in giving it a try?
Caffeine intake late in the day can certainly disrupt your sleep, but the caffeine in four cups (960 ml) of coffee finished even six hours before bedtime can reduce total sleep time by more than an hour, and that was in younger individuals. Older adults’ sleep appears to be more sensitive to caffeine. The same 400 mg of caffeine, which is less than what’s in a Venti-sized coffee from Starbucks, cuts total sleep time by about an hour in young adults (average age of 24), but that same amount cuts off more than two hours among the middle-aged (average age of 52). What about just a single cup (240 ml) of coffee at dinner? It can indeed cause a significant deterioration in sleep quality.
There are also consistent associations between drinking coffee and certain adverse outcomes during pregnancy, including miscarriage, early preterm birth, and low birth weight. Although coffee consumption has not been linked to common birth defects, it may increase the risk of childhood leukemia. For more on coffee and pregnancy, see my video on how much is too much.
Also, don’t stick it up your butt. A review on the questionable safety of coffee enemas warned against their use, citing reports of colitis, re**al burns, perforation, and fatal electrolyte disturbances.
Keep in mind that daily consumption of caffeinated beverages can lead to physical dependence. It’s no coincidence that Americans alone spend more than $100 billion annually on the stuff. Caffeine withdrawal symptoms can include days of headache, fatigue, difficulty concentrating, and irritability. Ironically, coffee’s tendency to become habit-forming could turn out to be a perk if coffee is indeed confirmed to slow down biological aging.