Benefits of caffeine: energy and focus in moderation
Caffeine is part of the daily routine of millions of people. Early-morning coffee, a cup of tea, or even dark chocolate are all common sources of this compound, which we almost automatically associate with alertness and feeling less tired.
However, its effects go beyond this sensation of being energized. Caffeine acts on the central nervous system, and there is scientific evidence of its influence on alertness and attention and on certain aspects of physical performance. Nevertheless, these effects depend on the amount consumed, the timing of consumption, and each person’s sensitivity. Therefore, understanding its potential benefits also requires knowing how much can be consumed and what may happen when it is overused.
What Is Caffeine and How Does It Work in the Body?
Caffeine is a substance found naturally in various plants, and therefore in foods and beverages such as coffee, tea leaves, guarana berries, kola nuts, and cocoa. It can also be added as an ingredient to certain foods, beverages, and food supplements.
After ingestion, it is absorbed quickly and almost completely, and exerts much of its effect on the central nervous system. To understand why it makes us feel more alert, we need to talk about adenosine, a substance that participates in the regulation of sleep and wakefulness and contributes to increasing the feeling of drowsiness the longer we stay awake.
Its Effect on the Nervous System
As the hours of wakefulness pass, sleep pressure increases. Caffeine acts mainly by blocking adenosine receptors, temporarily reducing some of its signals. This does not mean that caffeine supplies the body with energy, nor that it replaces hours of sleep; rather, it temporarily modifies our perception of fatigue and enhances alertness.
How Long Do the Effects of Caffeine Last?
The answer varies considerably from person to person. After consuming caffeine, its effects may last for several hours, because the body needs time to metabolize and eliminate it. Individual factors such as genetics, age, habitual caffeine intake, certain medications, and specific physiological conditions such as pregnancy also play a role. For this reason, a cup of coffee in the afternoon may not affect one person’s sleep while disrupting another’s. This variation in effects is one of the reasons why what matters is not only the amount of caffeine we consume, but also when we consume it.
Caffeine, Attention, and Focus
One of caffeine’s best-known effects is its ability to increase alertness and reduce drowsiness. This effect may be particularly useful at times when there is fatigue or when attention must be maintained for prolonged periods. Some studies link the consumption of low to moderate amounts of caffeine with improved attention and reaction time, at doses ranging approximately between 40 and 300 mg.
The evidence regarding more complex cognitive functions, such as long-term memory, decision-making, and certain executive functions, is less consistent. Therefore, from a scientific standpoint, it is more accurate to say that caffeine enhances alertness and certain attention processes than to present it as a solution that improves these aspects over the long term or in a sustained manner.
Caffeine and Sports Performance
Caffeine is one of the most studied substances in sports nutrition, as it has been shown that it may improve some aspects of physical performance, although the effect depends on factors such as dose, type of exercise, training level, and individual response.
Its sports-related effect was traditionally attributed to increased use of fat as an energy source. Today, it is considered that a large part of its benefits is explained by its action on the central nervous system.
By blocking adenosine receptors, caffeine may reduce the perception of effort and fatigue during exercise. This may help maintain performance for longer or face certain physical efforts with a lower subjective sensation of exhaustion.
These effects have been observed in different types of sports, such as endurance exercises and tests related to strength, power, and speed.
Is There a Recommended Daily Amount of Caffeine?
In this case, it is appropriate to speak of caffeine not as a recommended or maximum dose, but as an amount considered safe. According to the European Food Safety Authority (EFSA), intakes of up to 400 mg of caffeine per day, from all dietary sources and distributed throughout the day, are considered safe for the general healthy adult population. For single doses, this amount is 200 mg.
There are also situations that require specific considerations. In the case of pregnancy, the Authority establishes that a caffeine intake of up to 200 mg per day from all sources is safe.
Therefore, general figures should always be placed in the context of each person’s individual characteristics. It is important to note that caffeine may, in certain specific cases, support alertness and performance as backed by scientific evidence, but the key is to use it in moderation. Individual tolerance must be taken into account, and it should be avoided becoming a tool to constantly compensate for fatigue or lack of sleep.
What Happens When We Consume Too Much Caffeine?
Caffeine can be compatible with a balanced diet, but exceeding individual tolerance limits may cause certain effects that depend on the amount consumed, personal sensitivity, and the time of day.
Nervousness, Palpitations, and Digestive Discomfort
Symptoms such as restlessness, tremors, a feeling of nervousness, palpitations, or gastrointestinal discomfort may appear, especially when high amounts are consumed. These potential adverse effects are a clear indication that increasing the dose does not mean obtaining greater benefits.
Caffeine Can Also Affect Sleep
The timing of consumption is particularly important. Even after the stimulating effects are no longer noticeable, active caffeine may remain in the body for several hours. In this regard, EFSA indicates that a single dose of 100 mg may affect the duration and patterns of sleep in some adults, especially when consumed close to bedtime.
A systematic review and meta-analysis estimated that a cup of coffee containing approximately 100 mg of caffeine should be consumed approximately 9 hours before bedtime to minimize its impact on sleep. As a practical reference, if we usually go to sleep at 11:00 p.m., it would be advisable to have the last coffee at around 2:00 p.m.
Therefore, people who have difficulty falling asleep or who perceive their rest as unrefreshing should pay attention not only to the number of coffees they drink, but also to the time at which they drink them.
Alternatives to Caffeine to Support Energy and Combat Fatigue
When fatigue appears, automatically turning to another cup of coffee is not always the best strategy. If the feeling is persistent, rest, nutrition, and physical activity habits should be reviewed, and a specialist should be consulted when necessary. In addition, there are ingredients traditionally used in products intended to support vitality, or that contain nutrients related to energy metabolism, which can serve as alternatives.
Ginseng
Ginseng, especially of the genus Panax, has a long tradition of use related to vitality and resistance to fatigue. Among its most characteristic compounds are ginsenosides, which have been studied for their potential effects related to fatigue, with favorable results in some cases, although it is not correct to attribute to it the same stimulating effect as caffeine.
Guarana
Guarana seeds have traditionally been used for their stimulating capacity, as they naturally contain caffeine. Although it is usually presented as a plant-based or natural alternative to coffee, its stimulating effect is related precisely to this reason.
B Vitamins
B vitamins participate in numerous metabolic processes, and several of them are directly related to normal energy metabolism. This is the case for vitamins B2, B3, B5, B6, and B12, which contribute to normal energy metabolism, and some also contribute to reducing tiredness and fatigue (EFSA).
However, their mode of action is completely different from that of caffeine. Vitamins are not stimulants, and they do not produce an immediate increase in alertness; rather, their function consists of participating in the body’s normal physiological processes.
Therefore, consuming amounts greater than necessary does not necessarily mean having “more energy.” What matters is ensuring an adequate intake of these nutrients, especially when the diet does not provide sufficient amounts or when there is a specific nutritional situation that must be properly assessed.
Royal Jelly
Royal jelly is a substance produced by worker bees to feed larvae during their first days of life and to feed the queen. This substance contains water, proteins, carbohydrates, lipids, and various micronutrients and bioactive compounds, some of which are involved in normal processes related to energy metabolism. For this reason, royal jelly has traditionally been used as support during periods of fatigue or increased physical and mental demands.
Frequently Asked Questions About Caffeine
Is Caffeine Good or Bad?
This compound cannot simply be classified as “good” or “bad.” In moderate amounts it may have benefits for physical or mental performance, but a high intake may cause nervousness or sleep disturbances, especially in sensitive individuals. Moreover, people do not all have the same sensitivity to, or response to, caffeine.
How Much Caffeine Can I Consume per Day?
For a healthy adult, EFSA considers a total intake of up to 400 mg of caffeine per day, distributed throughout the day, to be safe.
Does Caffeine Improve Concentration?
There is favorable evidence regarding alertness and reaction time, although this varies from person to person.
Does Caffeine Improve Sports Performance?
It may improve different aspects of sports performance and reduce the perception of effort. The response depends on the dose, the type of exercise, and individual characteristics.
How Many Hours Before Bedtime Should I Stop Consuming Caffeine?
There is no universal time, because the rate at which it is metabolized varies between individuals. However, since its effects may last several hours, those who have difficulty sleeping should avoid consuming it during the hours before rest and observe their own sensitivity.
