Caffeine Keeps Morning People Up All Night, Leaves Night Owls Blissfully Unaffected

Illustration for article titled Caffeine Keeps Morning People Up All Night, Leaves Night Owls Blissfully Unaffected

Anyone who's ever had trouble sleeping has developed elaborate theories on how and why caffeine affects them. It's usually something along the lines of, "If I drink a cup of coffee after 11 a.m. on the third Tuesday of the month, I'll be up all night." But some new research is showing that the power caffeine holds over your sleep schedule might be affected by something as simple as whether you're a perky morning person or more of a late to bed, late to rise kind of person.

The study, which was done at Stanford University, wanted to test the affects of caffeine on people with different chronotypes, which is a fancy way of saying what time of the day they are most active and awake. Or, as most of us call it, morning people vs. night owls. Researchers asked fifty college students to track their caffeine consumption and when they woke and went to sleep for a week. They sampled the students' saliva to measure caffeine levels, and the participants also wore wrist monitors to record their movements, which helped researchers to determine if they had periods of wakefulness in the night.

The results showed that those students who were morning people and drank caffeine during the day were more likely to wake up in the middle of the night than their night owl counterparts who also consumed caffeine during the day. In terms of caffeine levels, the more caffeine the morning people had in their bodies, the more time they were awake during the night after an initial period of sleep. But this wasn't true for night owls.


The fact that they used college students as their sample makes this slightly unreliable because as we know, they tend to have very poor sleeping habits and are usually sleep deprived—since they're always up partying studying. But Jamie Zeitzer, one of the researchers, explained that this did have an upside because "it didn't matter how much caffeine they had." They usually had no trouble falling asleep. It was just once they were asleep that the caffeine had an effect.

It's hard to generalize these results to the whole population, but this was just the first study to connect chronotypes to caffeine effects. Next they plan on studying a diverse group of people. So someday, using that knowledge, you might be able to precisely determine the last possible moment you can have a coke during the day without it ruining your night.

For now, in terms of what this means for you, it's a bit hard to say because people's bodies clear caffeine at different rates. But, if you want to be on the safe side, if you're a morning person, you can skip coffee, tea, and whatever else jacks you up in the afternoons and evenings. If you're a night owl, feel free to go wild and guzzle mountain dew all the live-long day. Okay, that's a bit of an exaggeration, but you can probably get away with a nice afternoon latte without having to spend all night tossing and turning and wondering why you thought treating yourself to a little pick-me-up was such a smart idea.

Caffeine Disrupts Sleep for Morning People But Not Night Owls [MyHealthNewsDaily]


Image via silver-john/Shutterstock.

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Even though I tend to be a night owl, caffeine does not affect me at all. Probably because I grew up in a Latin American culture where there is no taboo against children drinking coffee (I always found it hilarious how Americans freak out when they hear that I've had coffee with my breakfast since essentially toddlerhood), so my body is just very used to it. I sometimes feel a bit deprived because I've never had the so-called "caffeine-buzz".