Coffee or caffeine has numerous effects on the human body. The following article shows the physiological effects, effects depending on the phase of life or lifestyle, interactions with nutrients and drugs, and observed results in various diseases.
Physiological effects of the alkaloid caffeine
General health
As in most cases, whether coffee has a positive or negative effect on health depends on the dose. In excessively high doses, the alkaloid caffeine can lead to fear, restlessness, nervousness, irritability, or even insomnia. Scientific studies indicate a threshold of around 1.2 g per day.
In the long term, consuming 2-5 cups of coffee a day can positively affect mortality. This was slightly reduced in studies. The combination of caffeine and alcohol has a negative effect. Cardiovascular disorders, as well as psychological and neurological complications, are documented here.
Cardiovascular system
Caffeine speeds up the heart, metabolism, and breathing. Blood pressure and body temperature rise slightly. The blood vessels expand, and the blood flows to all organs increases.
Concentration, alertness, attention
Drinks containing caffeine have a stimulating effect, activate the central nervous system, and increase mental and physical performance.
sleep
The alkaloid is stimulating and has a short-term positive effect on the state of wakefulness and performance. However, contrary to some speculation, this does not compensate for a sleep deficit. Quite the opposite: in some people, caffeine consumption hurts sleep behavior after a specific time (usually 4 pm / 5 pm). It can lead to problems falling asleep. This is probably due to genetic variants of the so-called adenosine receptor. This explains caffeine's effect: It binds to the receptor, blocks it, and thus increases alertness and reduces tiredness.
Water and electrolyte balance
Caffeine has a diuretic effect (promotes urination). However, even at doses of up to 400 mg daily, this does not have a negative impact on the water and electrolyte balance over a more extended period of time.
Effects on different phases of life/lifestyle
pregnancy
The analysis shows that the metabolism of caffeine slows down during pregnancy. It is then broken down more slowly and excreted from the body. A maximum of 200 mg per day is therefore set for pregnant women. Studies have shown that up to 3 cups of coffee a day does not affect birth weight, the number of premature births, or stunted growth cases. So far, there is insufficient evidence to confirm or refute the influence on birth weight and other endpoints related to pregnancy.
Sports
Caffeine increases lipolysis, which means that free fatty
acids can be used, and a glycogen-saving effect occurs. Consumption of 3-9 mg
per kg of body weight between 30 and 90 minutes before physical activity has
been shown to increase athletic endurance and performance