Effects on body and brain

Millions of people drink caffeine every day, but most are not aware of the lesser-known impacts caffeine can have on your body.

Caffeine is a stimulant and a psychoactive drug, meaning that it affects the brain directly. When caffeine enters the body, it prevents adenosine — a hormone that promotes sleepiness and interferes with dopamine release — from binding to its receptor and instead takes over. This explains why some people feel more alert or have a better mood after consuming caffeine.  

When consumed in moderation, caffeine can improve alertness, mood, and focus, and even decrease the risk of certain chronic diseases. However, excessive caffeine causes negative side effects, especially for adolescents. “According to the FDA, healthy adults may be able to tolerate up to 400 mg of caffeine a day [4-5 cups of coffee]. [… Likewise,] the FDA states that 1,200 mg of caffeine can cause toxicity, which can result in heart arrhythmias and seizures. Some energy drinks/shots have close to 300 mg of caffeine,” said Heidi Shah, health teacher.

However, because caffeine directly affects the brain, students should be wary about overconsumption. “Teens should avoid all substances that change the brain’s natural chemistry. Any time you introduce a stimulant to the central nervous system, it temporarily alters homeostasis, [the body’s tendency to return to stable, internal conditions]” said Shah. “[The] general advice for teens is to minimize or exclude caffeine from their diet.” The FDA recommends teens consume no more than 100 mg of caffeine per day.

The negative effects of caffeine tend to appear when daily consumption exceeds 400mg of caffeine. Immediate effects include rapid heartbeat and anxiety. “A big part of why I don’t have any caffeine before a test, no matter how tired, is because it’ll make me so anxious that I won’t be able to do my best,” said junior Amaris Tu. 

In addition, researchers have found that too much caffeine intake for teens can cause temporary health problems like nausea, irritability, nervousness and sleep problems, according to the National Library of Medicine.

Because of the dopamine release that results from caffeine intake, caffeine can be highly addictive, according to the National Institute of Health. For regular caffeine users, going without caffeine can cause painful withdrawal symptoms. “[By] one o’clock, two o’clock, I have the worst migraine of my life,” said Jessica Espy, science teacher, who usually drinks at least one cup of coffee every day. “I get a big headache.” Besides headaches, caffeine withdrawal symptoms can include agitation, anxiety, lowered awareness and a general sense of discomfort.

However, teenagers’ young brains are more easily manipulated, which not only results in students becoming addicted faster but also allows them to tolerate withdrawal with fewer long-term effects. “The teen brain is still growing, which means it’s more vulnerable to change when exposed to new substances like caffeine. However, the teen brain is also very resilient, which means it can bounce back quickly to homeostasis when the chemical is removed,” said Shah. 

Caffeine is everywhere, from coffee shops to sports energy drinks, and completely cutting it from one’s diet can be difficult. Nonetheless, students should consider reducing their intake because caffeine can have many negative consequences when overconsumed.