Is caffeine brain stimulation in a cup or a big gulp of jitters?

By Ryan Seeley

If you’re like me, your day starts with a cup of coffee. As you open the bag, the aroma fills the air and you can hardly wait to sit down and have that first sip. Maybe your first cup of the day comes from the drive-thru or perhaps you grab a coffee on-the-go from inside a coffee shop. Whatever your routine, coffee drinking is a daily habit most people would be less likely to skip than brushing their teeth.

Studies show that at least 80 per cent of adults in Western countries regularly consume caffeine in amounts large enough to affect their brain functioning. 

I’d argue that a river of coffee was absolutely necessary to get me through long nights of studying in graduate school, but what does health science say about caffeine? 

You’re probably familiar with studies that support the intake of caffeine. One, released just days before last Christmas, suggests that “Drinking four cups of coffee daily could reduce weight gain from a diet high in fat and sugar. Scientists at the University of Illinois found rats that consumed caffeine gained 16 percent less weight and accumulated 22 percent less fat than those that didn’t.” 

There may be some correlation or even causation, but I’d argue that skipping your third round of turkey would be a better choice. The major question with respect to caffeine shouldn’t be about limiting rat weight gain. Remember … rats will also choose cocaine over food, to the point of starvation and even death! 

Caffeine and the Human Brain

The impact of caffeine on the human brain depends on the individual. Most people report feeling more alert, more cheerful, more energetic, more productive, and more clear-headed after caffeine intact. I certainly experienced those reactions and used, as my late-night-study-session weapon of choice, a large Mocha Frappuccino. That combination of sugar and caffeine worked for me, putting the desire for sleep at bay.

Other people consuming the same concoction might become jittery, anxious, or get headaches. For some, that large Mocha Frappuccino could even increase the risk of a panic attack. It should also be noted that caffeine is mildly addictive, as it has some of the same qualities of stimulant drugs, although thankfully without the profound hazards.

The power of caffeine is often misunderstood. Unlike a typical stimulant, it doesn’t cause the brain to perk up or switch into high alert mode to enhance performance. Instead, caffeine works by blocking the neurotransmitter adenosine, whose function is to encourage the brain to quiet down and go to sleep.

Because caffeine is molecularly similar to adenosine, it stimulates the same receptors, thus displacing adenosine and preventing it from stifling such ‘upper’ neurotransmitters as dopamine. Sneaky caffeine disguises itself as adenosine and tricks the brain cells into staying alert.

Caffeine and Sleep

That late night cup of coffee doesn’t jolt you awake; instead, it suppresses your desire to sleep. Experts suggest that the caffeine in two cups of coffee can knock out half the brain’s adenosine receptors for as long as a couple of hours.   

Even small amounts of caffeine can have the desired effect of higher alertness, improved concentration, and reduced fatigue – but there is a limit. A study done at MIT showed that caffeine levels found in a ten-ounce mug of brewed coffee did boost performance scores on tests requiring alertness, concentration and fast reactions but after two cups of coffee, one taken in the morning and one in the afternoon, there were no increased benefits to consuming more.

A similar study using tea, which has less caffeine than coffee, found three cups spread out over the course of a day, was enough to reach the limit of usefulness. 

Caffeine and Memory

Some research suggests that caffeine can help sharpen memory. In a large study conducted at London’s National Addiction Centre, 9,003 adult caffeine drinkers were tested on verbal memory and visual-spatial reasoning. The result? Caffeine helped people’s scores.

Another study had participants take a drug that impaired both short-term and long-term memory. Those who then consumed caffeine dramatically reversed the impact of the drug. Caffeine users retrieved information from their long-term memory, recalled words from short-term and long-term memory tests, and had increased reading speeds. Researchers theorize that caffeine, in its suppression of adenosine, increases the activity of the memory neurotransmitter acetylcholine. 

Unfortunately, there’s a downside. Guzzling pots of coffee won’t get you any closer to developing nuclear fusion. Studies have shown that increased levels of caffeine can speed up decision-making but won’t improve the outcome of those decisions.

In fact, with increasing levels of caffeine, complex decision-making becomes strained, because users are quick to make decisions but may not take enough time to be thoughtful about their choices. It’s better, apparently, to get a good night’s sleep than to down a few cups of coffee prior to taking a test requiring management-level thinking. 

Caffeine Withdrawal

Many weekend headaches are thought to be caused by withdrawal from the workday quota of caffeine. Symptoms can include lethargy, irritability and muscle tension. Those who go cold turkey from caffeine may experience headaches as soon as 24 hours after quitting – headaches that may last as long as a week.

Thinking about quitting or significantly reducing your intake? Do so gradually, by one cup a day or combine decaf with regular coffee, increasing the percentage of decaf until you reach 100 percent. 

Are you one of those who brags about drinking coffee and going to sleep right away?  I’m about to burst that caffeine-perked bubble of yours. In one Japanese study, participants who drank 150 milligrams of caffeine one hour before bed took an average of 126 minutes to fall asleep. Those who didn’t consume caffeine took 29 minutes.

That stat doesn’t apply to you? That might be because you’re chronically exhausted and able to fall asleep quickly because you simply can’t keep your eyes open. This phenomenon has been explored in studies that indicated that caffeine users sleep about four-and-a-half hours – three hours less than non-caffeine users. Even when a late-night caffeine user falls asleep, brain activity is interrupted, causing enormous sleep cycle disruptions which, in turn, damage brain cells.

The best advice? Stop caffeine consumption by late-afternoon.  

Yes, Coffee Can Be Addictive

Although coffee doesn’t appear to be terribly harmful for most people, it does function like a drug in your body and can be addictive. Caffeine found in soda, tea and coffee works the same way, keeping you alert, but also causing higher levels of anxiety and sleep disorders.

Try decaf more often and, most importantly, get a good night’s sleep. While sleeping well is easier said than done, removing caffeine in the hours before going to bed could be a major factor in getting a better rest. Sleep well! 

This article originally appeared within the Spring 2021 issue. View the full issue here, or browse all back issues in the CRACKYL Library.