One of the things that I most enjoy is coffee, especially Puerto Rican coffee. There’s nothing better than that strong, but sweet taste that can get you up in the morning to do practically anything. When I was a kid, my mother used to have three cups per day, and I would follow her lead. Now, coffee at noon is my best chance. I barely have time to buy it in the morning, and my neuroscience training has thought me not to drink past 7:00 pm. But in recent days, I have committed the sin of taking a cup late at night, and I found out what a hellish nightmare it was.
Late Night Coffee and Its Consequences
After taking that sweet cup sent by god at 9:00 p.m., I notice that habitual sleepiness at 10:30 had stopped. I wasn’t drowsy and was full of energy, which made me finish a book and chat a little with my girlfriend. I knew what was happening, the sleep pressure that should act alongside the melatonin previously released by my brain was blocked. In other words, the hormone that makes different brain areas go to sleep-mode was not working. At 1:00 a.m. I was able to get to sleep, only to get up in various parts of the night and finish with a weak five-hour sleep.
My long day at work, which is basically a laboratory to research children and an educational program, was sluggish at best. I didn’t have the needed energy, and when doing more passive work, drowsiness started to conquer me. At noon I went straight to my car to take an hour-long nap and see if I could recuperate the sleep that I had lost previously (foolish of me, since I knew the answer to this). When I went back to work, nothing changed, and my efficiency wasn’t present all day. The way I processed information or made decisions was off. Any good cognitive ability I thought I had was non-existent. What was worse is that I knew all of this in advance, but my love for coffee made fall into this nightmare.
The Science of Sleep and Coffee
Brain scientists and medical doctors have been alerting the public on why coffee is a bad idea at night, in excess and for children; apparently, the three things that my mom did when I was a kid. The effect of caffeine is vast, but the main problems come with sleep, behavior, alertness, and cognitive processing. A recent review in 2017 in the Journal of Clinical Sleep Medicine investigated the impact of caffeine on kids in their sleep and their behavior. As they discuss, “caffeine consumption was significantly related to sleep routine, morning tiredness, and restless sleep in children, with increasing caffeine consumption correlated with increasing sleep problems.”
Why is sleep so devastating? There’s not just one factor, but the process of falling to sleep and the interruption brought on by caffeine is the biggest. Sleep is determined by two significant factors. First, is the circadian rhythm, which is basically a biological clock that signals the human body (including the brain) when to get up, when to sleep, pee, and go back to sleep – among other things. The rhythm is set to proximally 24-hours, which mean that your body knows when to go to bed and when to get up.
One of the signals that the circadian rhythm implement is the release of melatonin on the body. This hormone is now widely popularized in many health stores and indicates to the brain that it’s getting dark out there and it should go to sleep. This is through the suprachiasmatic nucleus, a part of your brain composed of at least 20,000 brain cells sitting on top of the brain.
But, as Matthew Walker, a neuroscientist from UC Berkeley explains, this is just part of the process. Moreover, melatonin, he tells, “has little influence on the generation of sleep itself.” As he describes in his amazing book, Why We Sleep, melatonin is like the timing official in an Olympic 100-meter race that says “runners, on your mark,” and then fires the starting pistol that triggers the race. As Walker later describes, “melatonin simply provides the official instruction to commence the event of sleep.”
Alongside the circadian rhythm and its use of melatonin, another process in the brain takes place, this one, deeply disturbed using caffeine. Sleep pressure, which implements adenosine, increases your chances of sleep by every waking minute. To have the feeling of adenosine on your body, imagine studying for a big test late at night and your eyes shutting down faster by the minute.
Speaking of tests, many students counter this feeling by pouring caffeine into their system. It sounds promising and useful, but it isn’t. What caffeine does is occupy the adenosine receptors and block the release of the hormone. By doing so, sleep pressure decreases, and you feel more alert and less sleepy to finish your studying for the next day’s exam. The problem, of course, comes when the caffeine starts to wear out. When caffeine completely leaves the body, all of that blocked adenosine pours out, and the sleepiness you had before the cup of coffee comes back with a punch of fury. Moreover, since you didn’t have a full night sleep (caffeine makes it complicated to sleep at night because it’s slowly processed by the liver), memory recuperation, emotional perception, and other cognitive abilities get downgraded. This is only one sample of the impact of caffeine, there are other processes and effects that I’m omitting.
Last Word on Coffee and Sleep Disruption
Recounting the devastating effects of caffeine and my experience with it after my cup of coffee late at night makes it obvious why I had the miserable day that I had. But, I’m not the only one, at least 90 percent of Americans consume some form of caffeine each day. What’s more problematic, hours dedicated to sleep is on the decline. America and their love for coffee may prove to be a ticking time bomb if consequences on the effects of coffee and other caffeine-base products on our health aren’t made clear. Moreover, it seems that the opioid crisis will soon find its match if caffeine doesn’t get an alert response from the public and the government. In my case, I have already started to break this problematic craving for coffee late at night and tried to push my consumption to just one cup a day.