The Properties and Effects of Caffeine
Caffeine is often associated with coffee, but it can be found in many other things, whether healthy or unhealthy foods and drinks. It’s used as a study aid, and when we’re not trying to stimulate our brains, it also plays a significant role in sports due to its energizing effects.
Some Interesting Facts About Caffeine
The discovery of caffeine is credited to German and French chemists. Although they were unaware of each other’s work, they almost simultaneously identified the compound in the 19th century. Friedrich Ferdinand Runge, a German chemist, was the first to extract caffeine from coffee beans.
Regarding its chemical and physical properties, caffeine is only slightly soluble in water. I’ve already written about this in my article Components of Coffee. It is a white, crystalline compound with a bitter taste. Its melting point is between 453–462 °F (234–239 °C).
Caffeine (chemical name: 1,3,7-trimethylxanthine) belongs to the purine derivatives and acts as a stimulant for the central nervous system. It can be found in over 60 plant species — for example, in coffee beans, tea leaves, cocoa beans, guarana, yerba mate, and kola nuts. These plants originally produce caffeine as a defense mechanism, since its bitter taste helps repel insects.
The Effects of Caffeine on the Body
One of caffeine’s most well-known effects is increased alertness and stimulation. It stimulates the brain, making us feel less tired. Although caffeine can give you a boost, its effects are not long-lasting—at least when it comes to coffee and energy drinks.
Most people have experienced that when we regularly consume caffeinated beverages, the effect tends to be short-lived. Sometimes it may even seem like the effect is no longer noticeable at all. It can be worth experimenting with the timing of caffeine intake if your body has become accustomed to it and it no longer produces the same effect.
Caffeine enhances mental performance, improves reaction time, and increases concentration, which is why many people consume it while studying or working. It is also popular among athletes because it increases endurance, stimulates fat burning, and delays the feeling of fatigue. For this reason, the International Olympic Committee listed caffeine as a banned substance for many years. Today, it is considered a permitted stimulant—but only in moderation. Excessive caffeine intake is still regarded as a form of prohibited doping.
However, the effects of caffeine vary from person to person. They depend on how sensitive the body is to caffeine, how quickly the liver metabolizes it, and how much caffeine is consumed on a regular basis. Some people experience heart palpitations after just one cup of espresso, while others can drink three double espressos a day without any side effects.
According to experts, up to 400 mg of caffeine per day is safe for most adults. During pregnancy, however, the recommended limit is no more than 200 mg per day, as caffeine crosses the placenta and may affect fetal development.
The Beneficial Effects of Caffeine
Although many people drink coffee primarily for its stimulating effect, caffeine can also offer several health benefits—when consumed in moderation.
- Boosts metabolism: Caffeine slightly increases the body’s energy expenditure, which is why it is found in some weight-loss supplements, such as green coffee capsules.
- Improves physical performance: It helps break down fatty acids, allowing the body to use fat more efficiently as an energy source.
- May reduce the risk of Alzheimer’s and Parkinson’s disease: Research suggests that long-term caffeine consumption may have a protective effect on the nervous system.
- May have pain-relieving effects: Caffeine is included as an active ingredient in some medications (such as headache remedies) because it enhances the effectiveness of painkillers.
- Improves mood: By increasing dopamine levels, it may help alleviate mild depressive symptoms.
It is important to note that these effects apply to moderate caffeine intake of about 200–400 mg per day, which is roughly equivalent to 2–4 cups of regular-strength coffee.
Side Effects of Caffeine
Caffeine side effects most commonly occur when intake is excessive. In such cases, it can cause heart palpitations and hand tremors. Other possible effects include heartburn, high blood pressure, and headaches. When these symptoms occur, a coffee allergy cannot be ruled out either.
Symptoms of excessive caffeine intake may include:
- restlessness and anxiety,
- sleep disturbances,
- rapid heartbeat,
- sweating,
- stomach discomfort,
- tremors and headaches,
- and in severe cases, caffeine poisoning.
The half-life of caffeine (the time it takes for the body to metabolize half of the consumed amount) is about 3–6 hours, but this varies from person to person. For this reason, drinking coffee in the evening can easily disrupt sleep, as caffeine may still affect the body even around midnight.
Although coffee can cause headaches, in many cases (and this has been my personal experience as well) it may reduce or relieve pain when consumed as lemon coffee.
How Does Caffeine Work?
After entering the bloodstream, caffeine begins to take effect within 15–45 minutes. It is absorbed in the stomach and small intestine, then travels to the brain, where it stimulates the nervous system. Blood pressure may rise slightly, heart rate increases, and levels of dopamine (the “feel-good” hormone) also go up.
Simply put, caffeine is a natural stimulant that enhances alertness and concentration. It works by interacting with a key brain chemical called adenosine. Under normal circumstances, adenosine is responsible for feelings of tiredness. Caffeine blocks adenosine receptors, preventing the brain from recognizing fatigue. As a result, we feel more awake and alert after consuming caffeine.
The twist is that caffeine does not actually provide energy, as many people believe — it merely suppresses the feeling of fatigue. This is why, when its effects wear off, we often feel even more tired than before. This phenomenon is commonly known as a caffeine crash.
How Much Caffeine Is in Coffee?
The amount of caffeine in coffee depends on the type of coffee you drink. Darker roasts contain more caffeine. Let me explain: darker-roasted coffee appears to have more caffeine because, to reach the same weight, more ground coffee needs to be placed in the portafilter. The more roasted the coffee bean is, the lower its density and weight, which means caffeine is present in a higher concentration by volume.
Even decaffeinated coffee contains some caffeine, although only in very small amounts. In decaf coffee, about 90–99% of the caffeine is removed. This can be done using a solvent-based process, the Swiss Water Process, or a CO₂ extraction method.
Caffeine Table:
| Coffee type | Caffeine content (mg/100 ml) |
|---|---|
| Brewed coffee (American-style, long coffee) | 40–80 |
| Espresso (double) | 80–175 |
| Ristretto (single) | 25–50 |
| Instant coffee (prepared) | Decaffeinated or 30–50 |
| Decaffeinated coffee | 1.5–2 |
In summary, caffeine content depends heavily on the type of coffee, roast level, grind size, and brewing method.
Caffeine in Other Drinks and Foods
Although coffee is the most well-known source of caffeine, it is not the only one. Caffeine can also be found in tea, cocoa, chocolate, energy drinks, and even in some pain relievers and dietary supplements.
| Product | Average caffeine content |
|---|---|
| Black tea (200 ml) | 40–60 mg |
| Green tea (200 ml) | 25–45 mg |
| Energy drink (250 ml) | 80 mg |
| Dark chocolate (100 g) | 50–100 mg |
| Cola (330 ml) | 30–40 mg |
| Guarana drink | can exceed 200 mg |
Caffeine and Health – What Does Science Say?
In recent years, numerous studies have examined how caffeine affects the human body. While it was once considered unhealthy by many, we now know that moderate coffee consumption is not only safe but may also be beneficial.
Research suggests that among people who consume caffeine regularly but in moderation:
- the risk of type 2 diabetes is lower (although several studies have also noted a temporary, mild increase in blood sugar levels after caffeine intake in people who already have diabetes),
- liver disease occurs less frequently,
- cardiovascular mortality rates are reduced,
- and fewer people suffer from depression.
It is important to note, however, that everyone reacts differently to caffeine. Genetic differences, body weight, age, and lifestyle habits all influence how much caffeine a person can tolerate well.
Caffeine in Sports
For athletes, caffeine is not only a stimulant but also a performance enhancer.
A cup of coffee before a workout may increase endurance, reaction time, and alertness. However, excessive caffeine intake can cause nervousness and dehydration, so finding your individual optimal amount is essential.
Caffeine and Sleep
The effects of caffeine on sleep are debated, but in general, caffeine can delay falling asleep and reduce the amount of deep sleep.
Since caffeine has a half-life of 3–6 hours, a cup of coffee consumed at 4 p.m. may still have noticeable effects around 10–11 p.m. For this reason, people who struggle with sleep issues are advised to avoid caffeinated beverages after 2 p.m.
Coffee Alternatives
For those who are sensitive to caffeine or simply want to reduce their intake, there are many alternatives available today. These include:
- chicory coffee,
- barley coffee,
- grain-based coffee alternatives,
- decaffeinated coffee (with the caffeine removed from coffee beans),
- and Ganoderma coffee, in which the active compounds of the mushroom help balance the effects of caffeine.
These options can be helpful for people who want to reduce their caffeine intake or experience stomach discomfort from coffee but don’t want to give up the experience of drinking it.
Would you like to be gentler on your stomach without giving up coffee’s energizing effect? Try DXN Ganoderma coffees, which naturally support the body without the typical side effects of caffeine.
Summary
Caffeine is much more than just a morning pick-me-up. It is a natural compound that has been known for centuries, helps keep us alert, improves concentration, and — when consumed in appropriate amounts — may even offer health benefits.
As with most things, balance is key. By being mindful of how much caffeine we consume and avoiding excessive intake, coffee can provide not only enjoyment, but also energy, improved mood, and even health benefits in everyday life.
