How does caffeine affect us and where to look for it besides coffee?

December 12, 2012

How does caffeine affect the human body? How much coffee or tea a day will not cause harm? Is it possible to get poisoned by caffeine? Let's figure it out.

Caffeine is rightfully considered one of the best natural stimulants. It reduces the feeling of fatigue, increases attention and improves mood. The main sources of this substance are coffee, tea, mate and chocolate. How does caffeine affect the human body? How much coffee or tea a day will not cause harm? Is it possible to get poisoned by caffeine? Let's figure it out.

Why does caffeine “invigorate”?

First, when caffeine enters the body, it mimics the neurohormone adenosine, which slows down nerve impulses and causes drowsiness.
Caffeine blocks adenosine receptors in the brain and other organs, preventing this substance from binding to them. Thus, it suppresses relaxation, increases attention and reaction speed. Secondly, caffeine stimulates the release of the hormone adrenaline, which increases the heart rate and blood pressure, and also increases blood flow to the muscles and provokes the entry of glucose into the blood from its depot in the liver. Third, caffeine increases levels of the neurohormone dopamine in the brain. This substance is responsible for feelings of well-being and happiness. It is the feeling of vigor and lift after a good cup of coffee that causes caffeine addiction. Caffeine: where and how much

We tell you where to look for caffeine, what its content in products depends on, and how to calculate how much caffeine you consume daily.

Caffeine in sports

First of all, caffeine is used by athletes as a stimulant (energy booster), which allows them to temporarily improve mood and performance. Caffeine improves concentration, neuromuscular interaction, and helps you train more focused and efficiently.

Another important effect of caffeine for sports, fitness and a healthy lifestyle is that it stimulates the breakdown of adipose tissue, increasing the amount of fatty acids in the blood. This has two important consequences: a reduction in body fat (which is why caffeine is a component of most fat burners) and allows fatty acids to be used for energy production by working muscles, saving glycogen and thus increasing work time, that is, increasing endurance.

There are numerous facts and serious studies that indicate the benefits of caffeine for athletes - it improves the performance of swimmers, rowers, increases testosterone levels, etc., but it is believed that in high-intensity sports caffeine is not as effective as in those where endurance is important .

Can caffeine help you sober up?

According to a common myth, caffeine is not only a strong tonic, but also a substance that can combat the effects of alcohol consumption. Scientists have proven that this myth is not true: it is impossible to sober up with caffeinated drinks, but it is easy to harm your body. Since caffeine creates the illusion of vivacity, and alcohol reduces attention and criticism of one’s own actions, the combination of these substances can push a drunk person to rash actions: driving a car, walking in the cold in light clothes, conflicts with others. In addition, the invigorating effect of caffeine does not allow a person to adequately assess the degree of intoxication and continue drinking alcohol. This can lead to serious poisoning.

Why is caffeine harmful?

So, caffeine deceives the nervous system. But that is not all. It increases the content of fatty acids in the blood. An increase in the content of fatty acids, plus stress, plus an increase in blood pressure - all these are prerequisites for myocardial infarction. Medicine is only now beginning to recognize the reality of this danger. Statistics show that people who drink a lot of tea and coffee are more susceptible to all diseases, not just heart attacks. In my medical practice, I have seen numerous cases of heart rhythm disturbances due to the consumption of caffeinated drinks. Often these disorders disappeared as soon as the patient stopped drinking coffee.

Caffeine causes the stomach to produce more acid, which can cause heartburn. Drinking large amounts of coffee can lead to stomach ulcers. I recently met with a colleague at the Mayo Clinic who told me that he refuses to treat any patient with a stomach ulcer unless the patient agrees to stop drinking tea and coffee.

By enhancing the production of catecholamines (epinephrine and norepinephrine), caffeine creates a stress effect in the body. This is one of the contributing factors to the high blood pressure often found in coffee drinkers. And high blood pressure is one of the main risk factors for heart attack.

The stress effect created by caffeine partially paralyzes intestinal activity. Digestion and absorption processes slow down. Food stays in the intestines longer and travels through the digestive tract for a longer time. This leads to increased gas formation and indigestion, which increases the likelihood of colorectal cancer.

Under the influence of caffeine, vitamin B1 is removed from the body, which ensures and regulates carbohydrate metabolism (including in the skin) and nerve function. With its deficiency, the quality of skin and hair deteriorates - they become dry, memory deteriorates.

Drinking coffee before bed is a surefire way to not get enough sleep. There are also difficulties falling asleep. For those who don’t understand (if you get up early, you know). In other words, a person who consumes coffee worsens not only his physical health, but also his mental health. As a rule, such people rarely dream or don’t dream at all. I think it’s worth recalling that we spend up to 1/3 of our lives sleeping and, as a result, healthy sleep is also the health of our spirit. Moreover, people draw some discoveries and interesting thoughts from their dreams. Seriously disrupting this process, a person becomes an “ordinary gray mass”, he is more controlled, and the level of perception of the surrounding world decreases.

A love of coffee can prevent a woman from getting pregnant, report scientists from Radboud University (Netherlands). The researchers came to this conclusion after completing a large study involving 9 thousand women. For 13 years, the participants in the experiment, who had previously undergone IVF, tried to get pregnant naturally. During this time, 1,350 women gave birth to children. Having examined factors that could promote or hinder conception, scientists concluded that drinking 4 cups of coffee, strong tea or other caffeinated drinks daily reduces the likelihood of conception by 26%. Now researchers are trying to explain how coffee impairs fertility.

Caffeine penetrates into mother's milk, therefore, regular consumption of coffee leads to a decrease in the amount of iron in milk (and the child suffers from its deficiency).

Caffeine is a terrible enemy!

When is caffeine safe?

For most people, a safe daily dose of caffeine is 300 mg
.
This is the equivalent of three small cups of strong coffee. However, do not forget that the level of caffeine in different types of tea, coffee and chocolate may vary. In addition, some people have increased sensitivity to caffeine. Already 100 mg
of this substance can cause unpleasant symptoms of an overdose. The lethal dose of caffeine ranges from 10 to 20 g. However, it is quite difficult to die from caffeine abuse. To kill a person weighing about 70 kg in such a sophisticated way, you would need to treat him to 100 cups of coffee at once.

How to consume caffeine

Traditionally, caffeine is consumed in the form of caffeine-containing drinks: coffee, tea, cocoa, guarana, and various energy drinks. In them (with the exception of energy drinks), caffeine is present in a natural form, often associated with other substances. As a result, caffeine has a milder and longer-lasting effect than pure synthetic caffeine. At the same time, caffeine is available in the form of tablets, capsules and other common forms of pharmacological preparations. Caffeine capsules are convenient for those who do not want or cannot take it in coffee and other drinks. You just need to keep in mind that caffeine in capsules or tablets acts more harshly than caffeine in drinks based on natural ingredients.

When is there too much caffeine?

The symptoms of a caffeine overdose are fairly easy to recognize. These include:

• cardiopalmus
• increased anxiety
• insomnia
• diarrhea
• frequent urination
• dizziness
• cramps in the stomach and intestines
• flushed face
• thirsty
• nausea
• headache

Symptoms of hypersensitivity to caffeine are very similar to those that occur with a caffeine overdose. Attention: they can occur when consuming products even with a small content of this substance - for example, chocolate!

Caffeine as a stimulant

In connection with the above, caffeine is often used as a psychostimulant, and most often its source is drinks based on caffeine-containing plants: coffee, tea, cocoa, guarana, mate, etc. However, caffeine is also used in medicine, therefore it is available in tablets and capsules. Doctors use it to eliminate headaches (especially in combination with analgesics), to enhance breathing and cardiac activity, to stimulate mental activity and increase physical performance, to relieve lethargy and drowsiness.

What makes you sensitive to caffeine?

• With age, sensitivity to caffeine increases.
• Women are more sensitive to caffeine than men.
• Cardiovascular disease increases susceptibility to the effects of caffeine.
• Irregular caffeine consumption. The less often a person drinks drinks rich in caffeine, the more sensitive he is to this substance.
• Interaction with medications. The compatibility of the medicine with caffeine is usually written in the instructions for use.
• Reduced weight increases sensitivity to caffeine.

Mechanism of action of caffeine

The main effect of caffeine is due to its ability to block phosphodiesterase, an enzyme responsible for the destruction of cAMP, a secondary transmitter necessary for the action of certain hormones, in particular adrenaline. As a result, the effects of adrenaline accumulate and intensify, leading to increased cardiac activity, nervous activity and other phenomena.

Another mechanism of action of caffeine is due to its ability to bind to adenosine receptors in the brain. Adenosine has an inhibitory effect, so the occupation of receptors by caffeine leads to a weakening of the inhibition processes and an increase in excitation.

Is caffeine a drug?

Caffeine is a stimulant that can be addictive
if consumed in excess on a regular basis. This substance is often called “the most popular legal drug in the world.” Abruptly stopping the consumption of caffeine-containing drinks can cause withdrawal symptoms. Generally, the more caffeine a person consumes, the higher their chances of developing unpleasant symptoms caused by the lack of caffeine. The first signs of “coffee withdrawal” begin 12-14 hours after the last cup of coffee or energy drink.

Quitting coffee: personal experience

Takzdorovo.Ru editor Snezhana Shabanova tells how to get rid of coffee addiction, and the portal’s regular author Maria Skatova shares her personal experience of giving up coffee.

Caffeine and creatine[edit | edit code]

Contrary to popular belief, caffeine does not destroy creatine molecules, however, the interaction of caffeine and creatine is still debated. Some studies show positive results when combining creatine and caffeine, others show negative results, and it is not yet completely clear who to believe. Summarizing modern scientific data, we can come to the conclusion that caffeine is indeed an antagonist of creatine, but the overall effect will be more positive than negative.

To explain, we can give an arithmetic example: the effect of creatine = 2, the effect of caffeine = 2. Creatine + caffeine = 3, (where the effect of caffeine = 2, and the effect of creatine = 1). Explanation: we will not get the same effect as expected due to a decrease in the effectiveness of creatine, but still the total effect will be greater.

So, caffeine does reduce the effectiveness of creatine, but using them together we get more benefits than using each separately. Therefore, it makes sense to purchase supplements that combine creatine and caffeine, if the latter is well tolerated. [8]

Read the main article:

creatine and caffeine

Caffeine during competition[edit | edit code]

If you want to get an extra performance boost during competition, eliminate caffeine or significantly reduce your caffeine intake in the days leading up to your race to reduce your tolerance to it. This way, when you reintroduce caffeine into your body, you will experience a more pronounced effect. Immediately before the race, take 50-200 mg of caffeine from a drink such as coffee (1-2 strong cups) or energy/sports drink (1-2 cans).

More on caffeine[edit | edit code]

Contrary to popular belief, caffeine taken immediately before exercise does not contribute to dehydration. In a 1997 Ohio State University study, six cyclists consumed caffeinated and decaffeinated sports drinks during a 3-hour pedaling session. The researchers found no differences in performance or urine volume during exercise. Urine production increased only during rest.

In another study in which 18 healthy men drank three different 1.75-liter drinks at rest, the caffeinated drink did not change their hydration.

Researchers from the University of Maastricht[9], the Netherlands, found that cyclists were able to hydrate equally well with both water and caffeinated cola after a long workout. A 2005 study from the University of Connecticut, USA, found that both caffeinated and decaffeinated colas kept athletes hydrated (between workouts) over three subsequent training days. During training sessions, athletes drank water, but hydrated with either a caffeinated or decaffeinated drink. A further study by the same researchers confirmed that moderate caffeine consumption did not increase urine production compared with placebo, and concluded that caffeine does not disrupt the body's fluid balance.

Caffeine for weight loss[edit | edit code]

Caffeine is often included in fat burners to increase metabolic rate and accelerate the burning of fat as a source of energy.

The effect of coffee and caffeine on appetite and food consumption.

A 2014 study by Schubert MM[10] examined the effects of coffee, caffeine, and decaffeinated coffee in humans. Scientists have found that neither coffee, caffeine, nor decaffeinated coffee affects food intake, hunger, gastric emptying rate, or glucose levels.

In an earlier study[11], the authors also reported no effect of coffee on appetite, but a slight decrease in food intake was observed. Another study [12] reports that decaffeinated coffee can slightly suppress hunger and increase satiety, while pure caffeine does not have such effects. Presumably this occurs due to the influence of other components of coffee, which increase the secretion of peptide YY.

In 2021, it was found that large doses of caffeine can increase appetite in rodents.[13]

As a result, we can conclude that coffee and caffeine do not have a significant effect on appetite and food consumption.

Application[edit | edit code]

A cup of coffee (237 ml) contains approximately 100 mg of caffeine. Observe what happens and compare the results with previous results when you did not drink coffee. In general, laboratory studies indicate that consuming doses of 3-6 mg per kilogram of body weight 30-60 minutes before exercise can improve both strength and endurance in well-trained athletes. However, the results obtained in laboratory conditions may differ from the results achieved in the usual conditions of the gym.

The best source of caffeine is black tea, which also contains other methylxanthines responsible for psychophysical activation. One bag contains approximately 40-50 mg, that is, to prepare an energy drink you need to brew about 5 bags (infusion time is approximately 10 minutes) (tea in bags is less effective than loose leaf). This should not be confused with chifir, where tea is brewed and harmful elements from the leaves are extracted.

You can also purchase caffeine sodium benzoate at the pharmacy. One tablet contains 40 mg of caffeine and 60 mg of sodium benzoate to improve caffeine absorption.

Also keep in mind that caffeine can aggravate certain medical conditions, such as ulcers, heart disease, high blood pressure and anemia, to name a few more serious ones. Listen to your doctor's recommendations. Above all, do not try to replace caffeine with natural, sensible nutritional practices aimed at improving athletic performance.

Caffeine in sports nutrition[edit | edit code]

In sports nutrition, caffeine is used as an energy accelerator. It has a pronounced stimulating effect, which allows you to increase the intensity of your workout, which in turn leads to accelerated burning of fat reserves and an increase in the load on muscles, thereby accelerating their growth. Helps you better concentrate on exercise technique. Caffeine is included in many fat burners, creatine with a transport system, pumping complexes, energy drinks and other supplements.

Almost every sports nutrition manufacturer produces supplements with guarana. It's actually long-acting caffeine with a number of other stimulants. Guarana is completely legal and inexpensive, making it one of the most popular tonics.

Caffeine is also present in most pre-workout supplements and fat burners. The most popular of them:

• NO-Xplode from BSN
• Jack3d (USP Labs)
• SuperPump250 from Gaspari Nutrition
• Universal - Animal Cuts
• NO Shotgun (VPX)
• SHRED-ULTRA from Millennium Sport Technologies (MST)

The best time to take caffeine supplements is 30 minutes before exercise. Almost all fat burners show their maximum effect when consumed before training.

Recommended caffeine doses[edit | edit code]

Optimal doses of caffeine depend largely on the physiological characteristics of the person and addiction. With the systematic use of caffeine-containing drinks and supplements, the body's tolerance increases; in this case, relatively large doses of caffeine of 200-400 mg are easily tolerated. In some people, overdose symptoms begin as early as 100 mg. Therefore, all caffeine-containing supplements should be started with a gradually increasing dose.

A systemic review[14] of the potential side effects of caffeine consumption in healthy adults, pregnant women, adolescents and children confirmed the following recommendations: ≤400 mg/day (4 cups of coffee) for adults, ≤300 mg/day for pregnant women, and ≤2.5 mg / kg / day for children and adolescents.