Timing your coffee: How late brews impact your sleep
For many people, coffee is an essential part of their morning routine. Its stimulating properties are widely recognised and appreciated. However, it's worth asking whether consistently reaching for a cup whenever you fancy it is truly beneficial.
Although it's difficult for many of us to imagine a day without a cup of aromatic coffee, it's crucial to be mindful of the times we choose to consume it. Even ardent coffee enthusiasts may experience negative effects from drinking coffee later in the afternoon or evening.
When shouldn't you drink coffee?
Caffeine, the main component of coffee, affects the body in various ways, depending on individual predispositions. There is no doubt that this substance impacts our circadian rhythm and the quality of our sleep. For this reason, it's wise to consider when to indulge in that last cup of this fragrant beverage. If you struggle with sleep problems or want to fall asleep more easily, you should definitely forgo the afternoon coffee.
Studies conducted in 2014, published in the "Journal of Biological Rhythms," revealed that individuals given a dose of caffeine equivalent to two espressos five hours before bedtime found it harder to fall asleep. Moreover, these individuals woke up more frequently, spent more time in light sleep (stage 1), and less time in deep sleep.
Drinking coffee in the afternoon, making it harder to fall asleep, can also negatively impact how easily you wake up. A 2015 study published in "Science Translational Medicine" suggests that a dose of caffeine taken three hours before sleep can shift our biological clock by about 40 minutes. This means a delay in the functioning of our circadian rhythms, which can make waking up in the morning more challenging.
When to drink your last coffee of the day?
Each of us is unique, and our reactions to caffeine vary. The time required to metabolise half the caffeine content after drinking coffee (or other caffeinated drinks) is an individual matter. For most people, about four hours are needed to eliminate half of the caffeine from the body. If you drink a cup of coffee containing 90 mg of caffeine, after four hours, 45 mg will remain in your body, and after another four hours, only 23 mg, and so forth.
Scientific research conducted by researchers from Wayne State University in Detroit, USA suggests that consuming coffee even six hours before bedtime can reduce sleep duration by an hour. Therefore, if you plan to go to bed at 11:00 PM, you should have your last cup of coffee no later than 4:00-5:00 PM. For individuals dealing with insomnia or who are particularly sensitive to caffeine, it is recommended to have the last cup of coffee preferably before midday.
