Cardiologist advises limiting coffee consumption to before 3:00 PM

Cardiologist Aurelio Rojas advises that caffeine consumption should ideally be concentrated in the morning and completed before 3:00 PM to avoid disrupting sleep quality. Because caffeine acts as a central nervous system stimulant by blocking adenosine receptors—the substances responsible for the natural urge to sleep—late afternoon consumption can interfere with the ability to achieve deep, restorative rest.

The impact of caffeine varies based on individual metabolism, age, sensitivity, and medication. According to the European Food Safety Authority, even a small dose of 100 milligrams can affect sleep patterns in some adults if consumed near bedtime. Furthermore, MedlinePlus notes that caffeine effects can last between four to six hours, though they may persist longer in certain individuals. Even if a person manages to fall asleep after consuming caffeine, the quality of that sleep may be diminished through delayed onset or reduced time spent in deep sleep phases.