Brace yourselves – we might have to replace our morning coffee ritual. After many social media users attributed mid-day energy crashes to consuming caffeine too early, researchers are delving into the potential advantages and drawbacks of postponing your morning caffeine fix.
"Everyone responds to caffeine differently," explained Marilyn Cornelis, a caffeine researcher at Northwestern University's Feinberg School of Medicine, in a recent interview with the New York Times.
The stimulant caffeine can hinder the ability to fall and remain asleep as it counteracts the effects of adenosine, a naturally occurring chemical that promotes sleepiness. According to Michael Grandner, who leads the sleep and health research program at the University of Arizona, it typically takes 20 to 30 minutes after ingestion for caffeine to be absorbed into the bloodstream and exert its effects.
Cornelis noted that genetics influence how long caffeine maintains alertness, with some individuals remaining energized after a single serving while others quickly feel the need for another dose just hours later. Grandner said he usually waits 30 to 60 minutes after waking before having his first coffee.
The reasoning behind delaying caffeine consumption is that since adenosine accumulates throughout the day, ingesting caffeine immediately upon waking provides a diminished boost as adenosine levels are lowest at that time.
Dr. Deborah Lee, a sleep expert at UK furniture company Get Laid Beds, also advocates waiting at least 45 minutes after rising before preparing that initial cup. "The cortisol [stress] hormone cycles according to your unique sleep pattern," Lee told the Mirror in February. "High cortisol levels can impact immunity, and if they peak as you wake, drinking coffee right after opening your eyes may do more harm than good and could even build caffeine tolerance over time."
However, Allison Brager, a neurobiologist with the US Army, informed the Times that research indicates regularly consuming caffeine has minimal effect on morning cortisol levels.
While Brager proposed that morning coffee can aid focus for workers and those exercising, she acknowledged delaying intake could extend caffeine's effects into the early afternoon. Both Grandner and Lee recommended avoiding caffeine within six hours of bedtime to promote restful sleep – at least we know when we should drink our last coffee of the day.
