Addicted to Caffeine?

Pietari Nurmi
Dec 29 · 3 min read

Caffeine is the most commonly used and the least regulated psychoactive stimulant. By affecting the nervous system and metabolism, it can decrease the feeling of tiredness and increase cognitive and physical performance. Caffeine consumption also has its downsides, as it is addictive when consumed regularly. When daily caffeine fix becomes the status quo, it gets harder to get your mental alertness to the same level than without it. At the same time, you build up your tolerance, and you need increased amounts of caffeine to get the same fix.

The most harming effect of caffeine is the decrease in sleep quality and difficulties falling asleep. People who consume caffeine the most, generally sleep more poorly and feel more tired during the days, even if they get their fix. Caffeine stays in your body quite a long time, and if you enjoy a cup of coffee in the afternoon, after few hours, the immediate effects wear off, but the long term influence stays until late in the evening. In adults, the half-life of caffeine is 5-7 hours, which means that a late afternoon cup of caffeine is still roaming in your body at midnight and disrupting your rest.

The affects are highly individual. If you are sensitive to caffeine and suffer from the consequences, even one cup of coffee can ruin your nightly rest. On the other hand, some people might consume a cup of coffee or tea in the evening, right before going to bed and even say that they sleep like a log. Even if personal, it can surely be said that the effects of caffeine on sleep are never good. However, it may be justified to consume caffeinated goods, but in moderation and with the correct timing. For example, you can ease the afternoon dip in your alertness with a cup of coffee after lunch. You can experiment with what works on you, but a good rule of thumb is that you should avoid caffeine after early afternoon if you wish to sleep without caffeine disturbing your sleep.

The highest amounts of caffeine can be found in coffee and energy drinks, but they are not the only ones. Also, tea, chocolate, and fizzy drinks such as cola have caffeine in them, and we suggest you drop them out of your evening menu.

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Additional Reading

Did you know that: Caffeine is not refreshing

Do you still remember how sleep pressure works? Adenosine, a neurotransmitter, is in charge of making you feel sleepy in the evening and increases sleep pressure. Adenosine grabs the receptors in your brain allocated to it, which increases the feeling of getting tired. Caffeine works similarly to being an antibody to adenosine. It grabs the same receptors and blocks adenosine’s way to your brain. When adenosine can’t influence your brain, you won’t feel as sleepy as you would normally. Caffeine’s ability to increase alertness is based on caffeine blocking sleep pressure. It does not make you more alert but makes tiredness go away. Also, there is no magical performance increasing abilities in caffeine, but it takes your cognitive and physical abilities to the same level as they would’ve been before.

Roehrs, T., & Roth, T. (2008). Caffeine: Sleep and daytime sleepiness. Sleep Medicine Reviews, 12(2), 153–162.

Walker, M. (2017). Why we sleep: Unlocking the power of sleep and dreams. Simon and Schuster.