What Happens To The Brain While Drinking Coffee?

JAKARTA - Have you ever felt like you needed another cup of coffee in the afternoon to keep your spirits up until working hours? Maybe you should reconsider.

A new study found an interesting fact, namely drinking two cups of coffee after noon can make our brains more active at night, even though they should rest. As a result, the conditions that arise can damage energy.

Researchers from Canada say caffeine, the most consumed stimulant in the world, can actually change the structure and complexity of brain activity during various stages of sleep.

"The widespread use of caffeine in society makes this topic an important health consideration. Understanding how caffeine affects sleep architecture and brain dynamics can help explain its impact on neurohealth," said Professor Philipp Th\"olke, lead of the study, quoted from the Daily Mail page.

Researchers from the University of Montreal analyzed the sleep patterns of 40 healthy adults with the habit of drinking moderate coffee, aged 20 to 58 years. These participants stayed two nights at the clinic.

One night after drinking 200 mg of caffeine (about two cups of coffee), and the other night after drinking the placebo (empty medicine). This research uses the double-blind method, meaning neither participants nor researchers know when participants are consuming caffeine or not.

The quality of participants' sleep is monitored using an electroencephalogram (EEG) device, which records brain activity by capturing the electrical signal produced by the brain.

With this EEG, researchers focus on some markers of brain complexity, such as how random brain signals are, how easily signals can be compressed, and how consistent signals are over time. They also see the distribution of electrical activity at various frequencies.

Research results show that caffeine mostly affects brain activity during non-REM sleep. This is a stage of sleep that is considered the calmest or the resting phase.

This stage is divided into different phases. A person falls asleep, then moves from mild sleep to deep sleep. At this point, the breath, brain activity, and heart rate usually slow, the body temperature decreases, and the movement of the eyes stops. This is a very important phase to recover, help the body repair tissue and muscles, and strengthen the immune system.

However, the researchers found that consuming caffeine after noon had a negative impact on this crucial stage, resulting in less restorative sleep or less restoring.

"Caffeine delays but does not prevent sleep, so although we can sleep under the influence of caffeine, the brain, and therefore also sleep, it is affected by the substance," Professor Th\"olke told PsyPost.

"This causes shallower sleep with increased information processing during the sleep stage where the brain usually enters a recovery inner rest," he added.

The researchers also noted that certain brain signals become flatter, suggesting that under the influence of caffeine, the brain is more similar to a critical state, where the brain is most responsive and adaptable.

This study also analyzes how age affects the impact of caffeine on the brain and sleep health. Generally, young adults aged 20 to 27 are more susceptible to caffeine stimulant effects during REM (rapid-eye-movement) sleep compared to middle-aged adults.

The researchers suspect this could be because older people have fewer adenosine receptors in the brain. Adenosine is a chemical that accumulates in the brain while we are awake and eventually makes us feel tired. Caffeine works by blocking this adenosine receptor, making us feel more awake. Because older adults have fewer receptors, the effects of caffeine inhibition may not be so effective, especially in REM sleep.

However, during non-REM sleep, caffeine effects are generally the same in all age groups. Therefore, the researchers concluded that caffeine has the ability to change brain structure and affect how well we sleep.

Even so, they admit that this study only involves healthy individuals, so that their findings cannot be generalized in individuals with neurological or psychiatric conditions such as restless leg syndrome or Parkinson's.

This study comes as many people experience sleep problems. A study from The Sleep Charity last year found that nine out of ten people had sleep problems. Bad sleep has been linked to various health problems, including cancer, stroke, and infertility.

Experts have long suggested that waking up at night does not mean insomnia. However, lack of sleep can cause many problems, ranging from being easily offended and less focused in the short term, to increasing the risk of obesity, heart disease, and diabetes.