In the year 2737 B.C. the Chinese Emperor, Shen Nung, was allegedly sitting under a tree when served a cup of steaming hot water. With little more than fate and some wind, leaves were blown into his cup and tea was discovered and quickly spread throughout Asia and beyond, though iced teas wouldn’t enter the scene until 1904.
An Ethiopian goat herder is credited for another discovery: after moving his goats to graze in a different pasture, he found that his herd grew more antsy and jittery. After closer observation, he concluded their behavior must be connected to the small berries they’d started eating. Inspired innovation would later lead the berries to be dried and separated, exposing their seeds which we all now know as “coffee beans.”
During Hernando Cortes’ expedition in Mexico, he recorded that the Aztec leader, Montezuma consumed cacao, a chocolate beverage, consumed as far back as the early Mayans.
In 1819, Johann Wolfgang von Goethe--yes, the poet--met with the physician Friedlieb Ferdinand Runge, who had already isolated numerous compounds from many substances. Goethe, fascinated by the chemist’s work, gave Runge a box of Arabian mocha beans to study, from which Runge first isolated and purified the scentless, bitter, white powder we call caffeine.
The origin stories and anecdotes go on and on, because, let’s face it: caffeine is the world’s most popular stimulant, and it comes from over 60 natural sources. According to the Radiology Society of North America, global caffeine consumption was approximately 76 mg per person per day in 2005 (though in the United States the estimate was significantly higher at 238 mg per person per day). Despite thousands of years of human consumption, there’s been a lot of modern debate about coffee consumption, and how big a role caffeine should play in our diets. After all, we hear from medical professionals that the dangers arise when and if you’re consuming “high” amounts of caffeine, which many define differently since actually consuming a lethal amount is all but impossible--the Mayo clinic claims that 400mg/day is considered “high”, and if this is your regular, you may consider cutting back. In case you were wondering, a bottle of selo contains 66 mg of caffeine, meaning you’d have to drink 6 bottles before hitting this mark.
But in the midst of the coffee pro-con hubbub and all the danger warnings for heavy caffeine consumption, it begs the questions: what exactly is happening inside our bodies when we consume caffeine to create these dangers and how should this affect our consumption habits?
First, let me note that the caffeine’s virtue-vice dichotomy is rooted in its biological evolution: poisoning undesirable insects, while enhancing the memory of pollen-spreading insects. Caffeine still has incredibly adverse effects on animal species like spiders, dogs and even horses. This has nothing to do with inherent danger in caffeine consumption, however, and everything to do with each species’ ability to metabolize the caffeine compound. So, what happens inside of us?
Have you ever noticed that when you drink caffeine its effect seems almost immediate? Well, that’s because it is. The caffeine compound passes through tissue membranes with ease. So when you sip a caffeinated beverage, caffeine doesn’t wait until it reaches the small intestines to enter your bloodstream like nutrients or proteins, it slips through the lining of your mouth, throat, esophagus and stomach. Nearly all caffeine content (approx. 99%) is travelling through your bloodstream within the first 45 minutes of your drinking it. Caffeine’s half-life, and your resulting “rush” lasts about 4-6 hours.
From the bloodstream, its course affects muscles and other tissues, and perhaps most noticeably, the brain. Its exact effect on muscles has been harder to isolate because of accompanying chemicals that are associated with caffeine intake. However, many studies have helped clear things up a bit, indicating that caffeine stimulates skeletal muscle and the breakdown of glycogen and lipids which enhances endurance and athletic performance. Though many have taken this and run with the idea that coffee can help in weight loss, other studies show that these effects may not be long-term solutions, as they wear off in those who consistently consume coffee.
Fun fact: if you were wondering why you have to use the restroom after drinking a lot of caffeine, it’s surprisingly not because you just drank a liquid (well, at least not entirely). It’s largely because theophylline relaxed your colon. This relaxing effect allows for greater blood flow, and more oxygen and nutrients that can be used by your brain and muscles--except that caffeine actually has the opposite effect, constricting the arteries in your brain.
Caffeine increases your heart rate, the force of its pulsation and general cardiac output. Studies testing the effects of caffeine showed that those who consumed doses greater than 250 mg experienced rapid heart rate and extra heart beats.
When caffeine enters the brain, it blocks adenosine--the biochemical responsible for slowing our neurons when we get tired--by interfering at the adenosine receptors. It’s molecular shaping is similar enough to adenosine to get effectively in the way, but not similar enough to still slow our neurons. This delays the pineal gland’s release of melatonin, which is responsible for your “feeling tired” and helps regulate your sleeping patterns. This doesn’t mean you’ve effectively put off your need to sleep, only that you’ve masked your drowsiness. This process also affects your dopamine, allowing it to work more efficiently. This is how it’s so easily associated to insomnia. The implied negative consequences can easily be averted, however, by not drinking caffeinated beverages in the window that your body usually gets tired.
In conclusion, are there dangers to drinking caffeine?
Sure, if it’s not consumed responsibly and in moderation, you will disrupt your sleeping schedule, which in and of itself can start a domino effect of issues like weight gain, irritability, etc. That being said, as long as your caffeine consumption remains under an “excessive” amount (more than 750-1000 mg) and you typically don’t drink it after 5 pm, it can be a part of a balanced, healthy daily diet. Because the contemporary drink industry extracts caffeine from its natural source and adds it to new beverages, greater health risks are actually associated with its neighboring additives, like sugar, artificial dyes, phosphoric acid, etc.