A Closer Look at the World's Most Common Drug

by Reyna Jones

Midterms. Finals. Deadlines. All-nighters.

How do we get through it? Whether it is coffee, tea, soda or energy drinks, we often find ourselves relying on caffeinated products to keep going strong. Caffeine has become a staple in aiding students to balance academics as well as social relationships. According to the National Institute on Drug Abuse, a reported 90 percent of Americans ingest caffeine every day, making it the most commonly used drug. Worldwide, a whopping 260 million pounds of caffeine is consumed every year. In addition to its benefit of increased alertness and motivation, caffeine might also reduce the risk of stroke, Alzheimer’s disease and even some forms of cancer. Research conducted at Harvard’s School of Public Health suggests that people who drink two to three cups of caffeinated coffee each day even lower their risk of suicide by 45 percent. Caffeine may decrease risk of suicide because it is thought to act as a mild antidepressant, positively impacting emotion by enhancing the effects of serotonin, dopamine and noradrenaline in the brain. Therefore, consumed appropriately, caffeine can offer many benefits.

Not surprisingly, there is also a darker side to caffeine. Taken out of moderation, caffeine can have a negative impact on overall health. Generally, 400 milligrams of caffeine (equivalent to four average cups of coffee) is considered safe for healthy adults, however, overindulgent caffeine use, exceeding 500 to 600 milligrams of caffeine each day, can be harmful.  According to Dr. Nadezda Povysheva, neuroscience professor at the University of Pittsburgh, “Wide consumption of energy drinks with high caffeine content can change our view on caffeine dependence and its addictive potential.” Side effects of caffeine overconsumption, similar to those sometimes experienced with highly caffeinated energy drinks include:  increased heartbeat, restlessness, anxiety and sleep difficulties.  

Caffeine is a trickster, deceiving your brain into thinking you are not tired. It readily penetrates the blood-brain barrier, entering the brain with ease, where it binds to adenosine receptors.  Generally, in the absence of caffeine, adenosine binds to these receptors and results in the feeling of being tired. Because adenosine is unable to bind to the receptors in the presence of caffeine, nerve cells are stimulated instead of inhibited, increasing alertness and delaying fatigue. Caffeine causes the brain’s chemistry and physical features to be altered over time. Additional adenosine receptors are developed and added to the cell membranes of neurons in order to maintain equilibrium. Hence, frequent coffee consumers develop a tolerance to caffeine, requiring more caffeine to block the increased number of adenosine receptors to yield the same desired outcome.

Caffeine is a stimulant that can cause mild physical dependence with continued use. The sudden stop of caffeine triggers withdrawal symptoms such as headaches, irritability and drowsiness. In fact, in the fifth edition of the Diagnostic and Statistical Manual of Mental Disorders, caffeine withdrawal is classified as a mental disorder. Since the brain has an increased number of adenosine receptors after continued caffeine use, lack of caffeine causes an imbalance and the brain is no longer in equilibrium. To break the dependence on caffeine it is reported that one must go through about seven to twelve days of the symptoms without caffeine while the brain decreases the number of adenosine receptors. Although caffeine withdrawal is not as significant as withdrawal from alcohol or other more harmful drugs, the next time you go to grab a caffeinated beverage, consider planning for a few more hours of sleep instead.