The Caffeine Conundrum

Note: the following was, quite appropriately, written in a coffee shop. 

In America, drowsiness is treated as an affliction. Americans seem to subscribe to the philosophy that work is done best early in the morning, or late at night (which is often more accurately termed as early in the morning, anyway). By harsh consequence, these times are also when people tend to be the most tired. So if it’s before the sunrise chasing commute, or in preparation for the midnight cram session, Americans turn in droves to the things that promise the pick-me-up they crave: beverages filled with the alkaloid trimethylxanthine, more commonly known as caffeine.

            What causes drowsiness in the first place? Like most physical responses, tiredness begins in the brain, where the binding of adenosine to specialized receptors causes eye droopage, fatigue, and the desire to put down the textbooks and go enjoy the cool side of the pillow. Enter caffeine, the Jesus of academia, which speeds up nerve cell activity where adenosine would slow it down. Caffeine inhibits the binding and subsequent effects of adenosine, put simply, because it looks like adenosine. At the chemical level, the two are so similar in structure that caffeine can bind to receptors that regularly accept adenosine. Since they are already occupied, the filled receptors will not take up adenosine and those sleepy symptoms dissolve with each finished page of your dissertation.

            What happens next is familiar to almost everyone. That cup of coffee, spot of tea, or liter of soda gives the user a feeling of heightened alertness and boosted energy. What’s actually happening is the brain entering into emergency situation mode. The presence of bonded caffeine activates the pituitary gland which responds in the same way as if the user were faced with a grizzly bear or accidentally cut their finger off when slicing potatoes. Hormones released from the stimulated pituitary gland trigger the release of adrenaline, the fight-or-flight hormone, from the adrenals. The body’s response to adrenaline is what gives caffeine its reputation as an energy booster; shortly after intake of caffeine, adrenaline causes the users heart rate to increase, his pupils and airways to dilate, his blood pressure to rise as blood vessels constrict, and his liver to release sugars into the bloodstream.

These effects begin almost immediately after caffeine ingestion, and are considered the short-term affects of caffeine. However, caffeine can have long-term effects as well, especially when consumed in large quantities and over an extended period of time. Of course, due to the frequency of consumption and the phenomenon of wildly exaggerated serving sizes in America, the long-term effects are just as notable as the short-term. Just 100mg of caffeine a day can lead to dependency and, with standard cups of coffee containing as much as 200mg of the drug, it can be terribly easy to fall into a caffeine addiction.

The threat of addiction is doubled by the other hormonal effect of caffeine, which is to increase dopamine levels in the brain. Dopamine is a neurotransmitter that activates the pleasure center of the brain; it makes a person feel good. With adrenaline and dopamine working in combination, caffeine users experience an effect that they tend to not want to give up. This leads people to picking up the coffee pot when the first cup wears off. With the average American consuming 300-400mg of caffeine a day, this puts many consumers well into the range of addiction.

Caffeine addiction can be highly detrimental to an individual’s sleeping habits. The body requires about 12 hours to metabolize and remove caffeine, so any caffeinated beverages consumed in the afternoon will probably remain in the body well after the individual has gone to sleep. Of course, the presence of caffeine will make attaining sleep difficult, but even when a person does fall asleep, it is likely to be unsatisfying. The presence of caffeine in the bloodstream during sleep prevents the deep sleep that the body needs to awake feeling well rested. And so the cycle continues when an individual wakes up feeling tired, and pours themselves another cup of coffee.

As the most widely consumed drug in the country, caffeine is found in coffee, tea, soda, energy drinks, and even chocolate milk. It is found in certain painkillers, for its blood vessel constricting effect, and is used medically as a heart stimulant and a diuretic.  Although it is produced naturally by many plants, humans often take its use to unnatural extremes. Continued use may actually increase the number of adenosine receptors, prompting users to consume more and more to reach the desired effect. Discontinuing use, therefore, will increase the normal effects of adenosine, as more receptors are present to be filled; this contributes to the intensity of withdrawal symptoms a person may feel which includes increased tiredness and headaches.

The popularity of caffeinated beverages seems unlikely to decrease as society pivots itself on long work days and stressful careers. Caffeine is almost a requirement of the American lifestyle, a point that Dunkin’ Donuts clearly corroborates with their tagline: “America runs on Dunkin’”.