Have you ever made this link? The days when you drink fewer coffee are followed by the nights when your dreams are the most perennial. Coincidence? Not necessarily. A recent study published in the journal Sleep suggests that stopping or decreasing caffeine changes our paradoxical sleep, this key phase where our dreams come to life.
Caffeine and sleep cycle: a narrow link
All this is not so crazy. Caffeine is a stimulant that acts by blocking adenosine, a molecule signaling to the body that it is time to rest. Result: falling asleep is delayed, fragmented sleep and reduced deep sleep. The caffeine half-life, which is between three and six hours, explains why a coffee made in the late afternoon can disrupt sleep.
On the contrary, by reducing caffeine, the body gradually regains a natural cycle. Sleep becomes longer and less chopped, and above all, the duration of the paradoxical sleep (REM) increases. It is during this phase that dreams are the most elaborate and memorable.
Why dreams become more animated
Then make a focus on this paradoxical sleep. This is not only associated with dreams, but also with their memory. Consequently, the more time we spend, the more the chances of waking up during this phase increases, the more memorable our dreams. This is how the authors of the Australian study explain it: this phenomenon of “rebound” of paradoxical sleep could explain why some people report more intense dreams after having reduced their caffeine consumption.
However, this effect varies from one individual to another and often only lasts a few days or weeks. And limits are possible. Dr. Jonathan Taieb, sleep specialist, stresses that the intensity of dreams does not only depend on caffeine: stress, certain drugs or sleep debt also play an important role.
The right timing to enjoy the coffee without harming sleep
Nevertheless, without completely banning caffeine, it may be interesting to respect a certain timing to preserve your nights and offer a recovery sleep. Experts recommend:
- Avoid caffeine at least eight hours before bedtime;
- Banking the high doses within 12 hours of sleep (for example, 100 mg up to 4 hours before bedtime, 400 mg can disturb sleep if consumed too late);
- Check the hidden sources of caffeine: sodas, chocolate, tea, supplements or certain drugs.
By adjusting its consumption and timing, it is possible to preserve the cognitive benefits of coffee while improving the quality of sleep and, potentially, the liveliness of dreams.
As Charlotte Gupta and Carissa Gardiner summarize, the authors: “Your sleep could thank you and your dreams could surprise you”.