It’s said that America runs on oil, but if that’s true, then it walks on caffeine. Americans drink 400 million cups of coffee a day, and who knows how much tea, energy drinks, and other caffeine sources on top of that. Caffeine is actually a psychoactive drug—the most widely used in the world—and millions of people depend on it every day to wake up and get going…or simply just to be civil. People have gotten so used to the idea of coffee and tea as a casual pick-me-up when we start to slow down that no one really thinks about what’s actually going on when we slurp down that pint of java three times a day. As it turns out, caffeine can do some pretty crazy stuff to your fragile, puny body.
Your brain produces a molecule called adenosine, which binds to receptors in your brain and slows down neural activity: it’s a natural process that’s thought to help you get to sleep at night but often makes you drowsy during the day. When you knock back that cup of joe in the morning, the caffeine is quickly absorbed into the blood and makes its way to the brain. There, it makes like a bad house guest and plops itself down in adenosine’s favorite armchair. But where adenosine makes you tired, caffeine doesn’t, and so every brain receptor that binds with caffeine is one that can’t make you tired. In other words, caffeine doesn’t have an agenda, and it called shotgun.
Caffeine has long been known to affect muscles, increasing activity and speeding contractions. And while that’s useful in an athletic sense, it’s useful in a more sedentary sense when applied to the intestines. Another theory is that caffeine increases the production of a hormone that stimulates the colon, which in turn stimulates the reading of newspapers in a locked room. But since researchers have reproduced the effect using decaffeinated coffee, that’s one theory that could probably use more fiber.
Increased energy is one of many parallel side effects that caffeine has on the body. When adenosine is blocked from making connections in the brain, it just sort of wanders off and tricks the brain into a mild fight or flight response. This inevitably leads to adrenaline being released, which makes your heart beat faster and harder and causes sugar to be released into your bloodstream. A similar effect can be achieved by standing next to a dangerous wild animal, but it’s not quite as convenient.
The next useful side effect of caffeine consumption is achieved as a result of the increased blood flow. As the heart beats faster, more blood moves through your body and through your lungs, leading to increased oxygenation, which is of crucial importance during sustained exertion and allows the muscles to operate more efficiently and with less effort. Caffeine also stimulates the metabolism, which means you’re burning more calories when you’re doing nothing. Don’t get your hopes up for a weight loss shortcut though, because potential caffeine-based weight loss programs are a shaky proposition.
As well as stealing adenosine’s seat, caffeine is something of an enabler to serotonin, dopamine, and other neurotransmitters that help the brain talk to itself. Norepinephrine is another neurotransmitter that’s produced in various parts of the body, and is especially good at speeding up brain function and improving concentration and memory retrieval. It also improves muscle function and efficiency. All very useful if you’re running from a sabre toothed tiger, as well as for getting that report finished by the deadline.
Caffeine is a bit of a wonder drug, and it wears many hats. One of those hats has the word “vasoconstrictor” written on it (no relation to the boa constrictor). Often when a person is experiencing a headache, the blood vessels in their brain dilate. Caffeine directly counters this by causing blood vessels to constrict, helping to reduce the pain. Caffeine is often added to migraine medication since the combination of caffeine with aspirin and acetaminophen can improve pain relief by up to 40 percent—and increase drug prices by 140 percent.
Unfortunately, for all the positive effects of caffeine on your body, there are a few negatives as well. As with many drugs, dosage is key. Almost anything, even water, can do you harm if taken to extremes, and that goes for caffeine as well. Most of the time, though, it’s not the excessive consumption that causes problems (at least not in the short term), but a sudden drop in consumption.
When someone consistently consumes high doses of caffeine, the brain adapts by creating more receptors for adenosine to bind to, creating a new normal. This effectively produces a kind of addiction (although not true addiction) since that person then becomes more susceptible to withdrawal symptoms if they cut back, including headaches, irritability, drowsiness, and difficulty concentrating, to name a few of the more pleasant ones. Raise your hand if that sounds like a your morning before you get your first cup of coffee. Then put your hand down and make a cup of coffee.
Drinking too much coffee doesn’t just leave a bad taste in your mouth, it can also have a negative effect on your guts. Caffeine increases acid production in your stomach as well as stimulating the muscles in your bowel. This usually happens when caffeine is ingested on an empty stomach and can lead to rushed bathroom visits—though this seems to be an actual goal for some people, who pay for a coffee enema to achieve the same effective result.
Although it can take as little as 15 minutes for caffeine to get to work after entering your body, it can take as long as six hours for your body to remove it again. And for all that time, you’re under its influence. That’s great if you take it at the beginning of a long shift, but not so good if you’re planning sleep any time soon. Because with all those extra hormones and neurotransmitters floating around your system, you’re unlikely to keep your eyes closed, and when you do finally fall asleep, it messes with your sleep patterns—resulting in less time spent in REM sleep. All this adds up to more fatigue, which equals more coffee, and the whole thing starts again. Caffeine sure picked an effective marketing strategy.
If you’ve ever wondered what it’s like to spend a year on the international space station, caffeine holds the answer…at least to one of the less pleasant side effects of space travel. That’s because one of the things shared by astronauts and people who consume large quantities of caffeine is a loss of bone density. The people most at risk of this are the elderly of course, but it’s definitely a possibility for someone looking to be extra authentic for their astronaut cosplay