Caffeine is one of the most widely used psychoactive substances in the world and an everyday aid to combat fatigue and increase alertness. From morning coffee to energy drinks and nutritional supplements, caffeine is an indispensable part of many people's daily lives. It is valued not only for its stimulating properties, but also for its positive effects on athletic performance and cognitive functions. In this article, you will learn everything you need to know about caffeine, its health benefits and how to use it optimally.

What is caffeine?

Caffeine is a naturally occurring alkaloid found in the leaves, seeds and fruits of over 60 plant species. It is known for its stimulating effects on the central nervous system and is often used to reduce fatigue and improve alertness. Caffeine blocks the action of adenosine, a neurotransmitter responsible for the feeling of tiredness, while promoting the release of dopamine and norepinephrine, which provide increased alertness and energy [1].

Caffeine occurs naturally in a variety of plants grown around the world. The most common natural sources are coffee beans, tea leaves, cocoa beans, and guarana. Caffeine has been consumed in various cultures for centuries, particularly in the form of coffee, tea, and cocoa. In modern times, caffeine is used in beverages such as coffee, tea, energy drinks, and also in dietary supplements, chewing gums, and capsules [2].

Caffeine can be extracted from natural sources such as coffee beans and tea leaves, or it can be produced synthetically. In industry, caffeine is extracted from raw materials and incorporated into beverages, foods or dietary supplements. Synthetic caffeine, which is chemically identical to natural caffeine, is often used in energy drinks, soft drinks and dietary supplements because it is cheaper to produce [3].

Health Benefits of Caffeine

One of the most well-known benefits of caffeine is its ability to increase energy levels. Caffeine acts as a stimulant that activates the central nervous system, thereby reducing fatigue. It blocks the adenosine receptors in the brain that normally cause the feeling of tiredness, thus leading to an increased feeling of alertness and increased energy levels [4]. This makes caffeine particularly useful for people who have to get up early or need an energy boost during a long day at work.

In addition to its energy effects, caffeine is also known to improve cognitive function. Studies show that moderate amounts of caffeine can improve attention, concentration, and reaction time. Caffeine increases the production of neurotransmitters such as dopamine and norepinephrine, which promote alertness and mental clarity [5]. Many people therefore use caffeine to increase their mental performance during demanding tasks or during intense periods of study.

Caffeine is often used by athletes to improve physical performance. It acts as a stimulant that promotes the release of fatty acids from adipose tissue and encourages the body to use fat as an energy source. This helps improve endurance and delay fatigue. Studies show that caffeine can significantly increase athletic performance in endurance sports such as running, cycling and swimming [6]. In addition, caffeine can support muscle contraction and reduce perceived exertion during exercise.

Caffeine is also commonly used to aid fat burning. It stimulates metabolism and increases thermogenesis, the process by which the body converts calories into heat. As a result, caffeine can increase calorie expenditure and improve fat burning, making it a popular supplement for people looking to lose weight [7]. When combined with a healthy diet and regular exercise, caffeine can help reduce body fat and improve physical composition.

How does caffeine work in the body?

Caffeine works in the body by blocking the adenosine receptors in the brain that are normally responsible for the feeling of tiredness. This increases the release of stimulating neurotransmitters such as dopamine and norepinephrine, which promote alertness and concentration. Caffeine also stimulates the central nervous system and improves the release of fatty acids from fat reserves that can be used as an energy source. In addition, it increases thermogenesis and metabolism, which contributes to fat burning [8].

Difference between theine and caffeine

Although theine and caffeine are often considered different substances, chemically they are the same compound. However, the two terms describe the same molecule in different contexts: caffeine in coffee is commonly called "caffeine," while the caffeine in tea is often referred to as "theine." The difference lies more in the effects, which are influenced by other components in tea, primarily the amino acid L-theanine and polyphenols. These have a calming effect and cause the caffeine in tea to be absorbed more slowly. This is why many people find the effects of tea to be gentler and longer lasting compared to the quick energy boost of coffee.

Caffeine content in various beverages: coffee, black tea, green tea, matcha and more

The caffeine content varies greatly depending on the drink and method of preparation:

• Coffee : A cup of coffee (240 ml) contains on average about 95 mg of caffeine, but varies from 70 to 140 mg depending on the variety and strength.
• Black tea : Black tea contains about 40-70 mg of caffeine per cup (240 ml), depending on brewing time and variety. However, it has a milder effect than coffee due to its higher polyphenol and L-theanine content.
• Green tea : The caffeine content in green tea is 20-45 mg per cup, making it a milder source of caffeine. The effects are calming and long-lasting, often perceived as less "stimulating" than coffee.
• Matcha : Matcha tea has a higher caffeine content than regular green tea, with around 70 mg of caffeine per cup (240 ml). Matcha also contains L-theanine, which harmonizes and prolongs the effects of caffeine.
• Energy drinks : A can of energy drink (250 ml) usually contains 80-120 mg of caffeine, which can be enhanced by additional ingredients such as taurine.

These variations make it possible to consume caffeine in different amounts and forms of effect, depending on whether a quick source of energy or a longer-lasting pick-me-up is preferred.

Recommended dosage and use of caffeine

The recommended dosage of caffeine varies depending on individual needs and tolerance, but is usually between 100 and 400 mg per day. A cup of coffee contains on average about 95 mg of caffeine, while energy drinks and supplements often contain between 50 and 300 mg of caffeine per serving. For athletic purposes, doses of 3 to 6 mg of caffeine per kilogram of body weight are often used to increase performance [9]. It is important to consider individual tolerance and not to overdo caffeine intake.

Caffeine can be consumed at different times of the day depending on the goal. For a morning energy boost or to increase mental performance, caffeine is usually consumed shortly after waking. Before exercise, caffeine is often consumed about 30 to 60 minutes before starting to maximize athletic performance. Since caffeine has a half-life of about 4 to 6 hours, it should not be consumed too late in the day to avoid sleep disturbances [10].

Side effects and safety of caffeine

Caffeine is generally considered safe when consumed in moderate amounts. Most people can consume 200 to 400 mg of caffeine daily without experiencing adverse effects. However, in sensitive individuals or in higher doses, caffeine can cause side effects such as nervousness, tremors, rapid heartbeat, or difficulty sleeping. Pregnant women should limit their caffeine intake to a maximum of 200 mg per day to minimize the risk of complications [11].

The most common side effects of caffeine include nervousness, restlessness, tremors, heart palpitations and insomnia, especially when consumed in excess. People who are sensitive to stimulants should reduce their caffeine intake or switch to caffeine-free alternatives. At very high doses, caffeine can cause more serious side effects such as high blood pressure or gastrointestinal discomfort. It is recommended to monitor individual tolerance and adjust caffeine intake accordingly [12].

Caffeine compared to other ingredients

Caffeine and L-theanine are often used together to increase mental performance. While caffeine acts as a stimulant and increases alertness, L-theanine has a calming effect that simultaneously promotes concentration without causing drowsiness. This combination is particularly popular because it can enhance the positive effects of caffeine while reducing the negative side effects such as nervousness [13].

Guarana is a natural source of caffeine, often used in supplements and energy drinks. Guarana contains more caffeine than coffee beans and is absorbed more slowly by the body, resulting in a longer and more consistent energy release. While caffeine from coffee acts faster, guarana can provide longer-lasting but smoother energy, making it a good choice for people who prefer a more consistent effect [14].

Natural Sources of Caffeine

Caffeine is found in many natural sources, including coffee beans, tea leaves, cocoa beans, and guarana seeds. These sources are consumed worldwide in beverages such as coffee, tea, and cocoa. While coffee and tea are the most well-known natural sources, dark chocolate also contains caffeine, as do some more exotic plants such as yerba mate and guarana. For people who don't want to drink coffee, there are many caffeinated alternatives [15].

Final Thoughts on Caffeine

Caffeine is a proven and effective substance that can increase both physical and mental performance. It offers a natural way to gain energy, improve concentration and increase athletic performance. Whether as coffee, tea, capsules or gummy bears - caffeine is versatile and easy to integrate into everyday life. To achieve the best results, however, you should always ensure that you use a moderate dosage to avoid negative side effects.

references

[1] Examine.com. Caffeine. Available at: https://examine.com/supplements/caffeine/
[2] WebMD. Caffeine - Uses and Benefits. Available at: https://www.webmd.com/vitamins/ai/ingredientmono-979/caffeine
[3] Healthline. Caffeine: Benefits, Uses, and Side Effects. Available at: https://www.healthline.com/nutrition/caffeine
[4] Examine.com. Caffeine and Energy. Available at: https://examine.com/supplements/caffeine/
[5] Mayo Clinic. Caffeine for Cognitive Health. Available at: https://www.mayoclinic.org/drugs-supplements-caffeine/art-20363372
[6] National Institutes of Health. Caffeine and Athletic Performance. Available at: https://pubmed.ncbi.nlm.nih.gov/12749483/
[7] Examine.com. Caffeine and Fat Burning. Available at: https://examine.com/supplements/caffeine/
[8] Healthline. Caffeine Effects on the Body. Available at: https://www.healthline.com/nutrition/caffeine-effects
[9] Examine.com. Caffeine Dosage and Usage. Available at: https://examine.com/supplements/caffeine/
[10] Mayo Clinic. Caffeine Supplementation Forms. Available at: https://www.mayoclinic.org/drugs-supplements-caffeine/art-20363372
[11] WebMD. Caffeine Side Effects and Safety. Available at: https://www.webmd.com/vitamins/ai/ingredientmono-979/caffeine
[12] Healthline. Side Effects of Caffeine. Available at: https://www.healthline.com/nutrition/caffeine-side-effects
[13] Examine.com. Caffeine vs. L-Theanine. Available at: https://examine.com/supplements/l-theanine/
[14] Examine.com. Caffeine vs Guarana. Available at: https://examine.com/supplements/guarana/
[15] National Institutes of Health. Natural Sources of Caffeine. Available at: https://pubmed.ncbi.nlm.nih.gov/12749483/