Afternoon coffee: A sleep disruptor explored through scientific studies
21 February 2024 19:23
Even habitual coffee drinkers could face adverse effects from partaking in an afternoon or evening cup. How caffeine impacts the body varies from person to person, based on individual characteristics. However, there is no denying that caffeine can interfere with our body's internal clock and impact the quality of our sleep. So, when should we treat ourselves to our final cup of this aromatic beverage?
When should you avoid coffee?
If you're struggling with sleep or simply want to fall asleep effortlessly, you should steer clear of afternoon coffee. A 2014 study published in the "Journal of Biological Rhythms" revealed that individuals who consumed a dose of caffeine equivalent to two espressos, five hours prior to sleep, experienced difficulty in falling asleep. What's more, these individuals frequently woke up, had longer periods of disturbed sleep during phase one, and shorter periods of slow wave, or "deep", sleep.
Afternoon coffee - due to its sleep-disrupting properties - can also hinder the waking up process. A 2015 study, published in the journal "Science Translational Medicine", showed that a dose of caffeine consumed three hours prior to sleep, set back the human circadian rhythm by roughly 40 minutes.
It's also noteworthy that caffeine acts as a diuretic and could increase the urge to urinate. Consequently, consuming coffee in the afternoon or evening can disrupt healthy, uninterrupted sleep due to physiological needs.
When should you have your last cup of coffee?
The answer to this question isn't straightforward. Everyone has a unique body and an individual tolerance to caffeine. How long it takes to rid the body of half the caffeine, after consuming coffee (or other caffeine-infused beverages), varies from person to person. Most people require approximately four hours to eliminate half the caffeine from their system. For instance, if a cup of coffee contains 90 mg of caffeine, after four hours, you'll have 45 mg left in your system, and after another four hours - 11.25 mg, and so forth.
"Each person has a unique tolerance to caffeine. Regular coffee drinkers who encounter problems falling asleep may find it beneficial to limit their coffee intake during the afternoon and evening hours," advises Professor Derk-Jan Dijk from the University of Surrey, in an interview with the BBC.
Research undertaken by American scientists from Wayne State University in Detroit suggests that even drinking coffee six hours before bedtime can reduce sleep duration by roughly an hour. Therefore, if you plan to hit the sack at 11 pm, you should finish your last cup of coffee no later than 4-5 pm. Those who suffer from insomnia or are particularly sensitive to caffeine, are advised to have their last coffee ideally before noon.
Source: eatthis.com
