Q: I heard that drinking coffee first thing in the morning can interfere with my ability to feel awake and can lead to an afternoon energy crash. Is that true?
This is an idea that was popularized by internet influencers:They say that if you avoid caffeine for 90-120 minutes after waking up, you’ll naturally perk up, avoid that nasty afternoon slump, and sleep better.
Proponents explain the idea as if it were supported by good evidence, and some people who have tried the method claim that “was a game changer”for their energy levels.
However, scientists studying the link between caffeine and sleep say that while there may be some benefits to skipping coffee in the morning, there isn’t much research to back up the claims.
Experts warn that in some cases, the risks of delaying your morning coffee may outweigh the supposed benefits and even prove hazardous.
How caffeine works and how long does it last?
During the day, the body produces a chemical called adenosine, which binds to receptors in the brain and causes drowsiness. Caffeine stimulates by blocking those receptors, said Marilyn Cornelis, a caffeine researcher at Northwestern University Feinberg School of Medicine.
But you don’t feel the stimulating effects of caffeine right after your first sip, said Michael Grandner, director of the sleep and health research program at the University of Arizona. Caffeine takes about 20 to 30 minutes to absorb into the bloodstream, reach the brain and make you feel more alert, he said.
The length of time caffeine keeps us alert “varies considerably,” says Dr. Cornelis, and is partly dependent on our genetic makeup.
Some people can drink one cup of coffee in the morning and “get through most of the day on that,” she said. Others clear caffeine from their system more quickly and may want to have another cup within a few hours, she added.
“Everyone responds to caffeine differently,” Dr. Cornelis said, so there is no one-size-fits-all solution when it comes to when to take caffeine.
Evidence for and against delaying the effects of caffeine
Because adenosine levels in the brain drop during sleep, they are lowest right after waking, Dr. Grandner said. So when there is little adenosine for caffeine to block, your first cup of coffee will give you less of a boost—or “less bang for your buck,” Dr. Grandner said—than when adenosine levels are high.
Another potential reason for delaying morning caffeine is the desire to have caffeine only once a day, Dr. Cornelis said. Scheduling it for later in the morning can aid extend its effects into the early afternoon, potentially counteracting the drop in alertness at that time.
As Dr. Grandner stated, there is nothing wrong with drinking caffeine right after a meal.
Although some on-line supporters suggest that doing so will disrupt the body’s normal wakefulness process by disrupting the body’s natural cortisol surge, but there is little evidence for this. The few small studies Studies that have examined caffeine’s effects on cortisol have found that in people who regularly consume caffeine, it has little effect on morning cortisol levels, said Allison Brager, a neurobiologist with the U.S. Army.
The reality is that many people don’t sleep enoughso if you need to be alert first thing in the morning, caffeine could be a lifesaver, Dr. Brager said. Studies have shown that caffeine can increases mental sharpness and physical fitnessFor soldiers driving bulky trucks, firefighters working night shifts or surgeons scrubbing in after morning procedures, delaying caffeine “can be a recipe for disaster,” Dr. Brager said.
If you exercise early in the morning, she added, it makes sense to have caffeine as soon as possible because it can improve your workout.
Dr. Grandner said it’s also okay to drink another cup of coffee (or another source of caffeine) if and when your energy levels dip around noon. Just avoid drinking it within six hours — or eight to 12 hours if you have trouble falling asleep — of going to bed.
Remember, adds Dr. Grandner, that coffee and tea contain more than just caffeine: these beverages are also excellent sources of antioxidants and beneficial plant compounds, which may explain some of their health benefits.
Coffee also helps many people have regular bowel movements. And for most of us, the morning ritual of drinking coffee offers a uncomplicated source of pleasure. What could be more optimal than that?
