From time to time you read that someone has given up coffee because they are doing a "detox".

Others advise to refuse, because it "washes out" calcium and dehydrates the body, others say that fasting is not possible, because it irritates the stomach and intestines, the fourth - that it provokes cancer.

However, despite the horror, people continue to drink this drink.

I wrote a lot about coffee.

But today I would like to talk about how it invigorates and how to use this property of its with maximum benefit.

Coffee is a tonic drink, several sips of which contain thousands of biologically active substances.

Among these substances there is

caffeine

, thanks to which coffee gives a feeling of cheerfulness, energy, sociability, and good health. 

After we drank a cup of coffee, after 45 minutes almost 90% of caffeine enters the blood and this feeling of vigor and energy lasts for another 2.5-4.5 hours, then caffeine is excreted from the body and it is replaced by light fatigue, especially , if it is already afternoon and, especially, in the evening.

This happens because caffeine acts on neurons (brain cells) in a certain way: it attaches to receptors on their surface, they are called adenosine.

What are adenosine receptors for?

During the day, cells produce a substance called adenosine.

It is produced from the ATP molecule (adenosine triphosphate), which is the body's energy currency.

In the morning, when we are alert (or relatively alert), we have a lot of ATP, because we slept and rested during the night (the more ATP, the more alert we are).

But the day goes by, we work, our brain works, and fatigue comes imperceptibly.

This happens because three phosphate molecules are gradually detached from the ATP molecules in the neurons and adenosine molecules remain.

Each detached phosphate molecule is a portion of energy for proteins that perform different jobs.

The more adenosine becomes, the more tired and sleepy we feel.

An increase in adenosine is the body's signal that energy reserves are depleted.

Considering that adenosine receptors are not only in the nervous system, but also in the cardiovascular, respiratory, excretory and gastrointestinal tracts, we feel less energy in the whole body: the myocardium (heart muscle) works weaker, the vessels relax .

This fatigue is the body's signal that it's time to rest.

But instead of sleeping for at least 10-15 minutes and replenishing ATP reserves, gaining real energy, we make ourselves a cup of strong coffee and it really activates us.

More precisely, caffeine molecules block adenosine and displace it from receptors;

about 5 minutes after they got into the blood, and the neurons can't rest.

As a result, neurons are activated and release neurotransmitters, we can again perceive information, make decisions, muscles are ready for work again.

Everything you need to know about coffee / Photo: Credits

Not just caffeine

Caffeine is a weak psychostimulant.

An example of a strong competitor of adenosine receptors is amphetamine, the weakest is theophylline (in dark

chocolate

).

If we drink coffee every day and a lot, we can develop insensitivity to caffeine over time.

This is a condition when new adenosine receptors begin to form on the surface of cells and adenosine molecules "sit" on them, despite caffeine.

So the body seeks to protect itself from excessive stimulation and rest.

It manifests itself in the fact that a person drinks and drinks coffee, but there is no feeling of vigor, on the contrary, fatigue sets in earlier and in order to tone up, more and more coffee is needed, and more time is needed to restore the body.

This leads to the fact that ATP reserves are reduced and other organs that need energy suffer.

Therefore, the maximum reasonable dose of caffeine is 300 mg per day.

Crossing this limit puts you at risk of overtiredness and cardiovascular problems.

To get rid of caffeine addiction (when you need a lot of coffee every day), the number of cups of coffee is reduced gradually.

Everything you need to know about coffee / Photo: Credits

But there are nuances:

Coffee affects different people differently.

This is because we have inherited different genes that control adenosine receptors: some are more sensitive, others less so;

and ability to metabolize caffeine.

Is coffee useful or not?

Useful, but it all depends on the dose.

There is evidence that those who drink coffee in moderation live longer.

What are the benefits of coffee:

  • It has a positive effect on the work of the liver and the immune system.

  • It reduces the risk of heart diseases (reduces the level of the pro-inflammatory protein interleukin-1-beta) and inflammation in general, improves the condition and functioning of blood vessels.

  • It reduces the likelihood

    of type 2 diabetes

    , liver cancer, prostate cancer, and some types of breast cancer.

  • May reduce the risk of neurodegenerative diseases, particularly Alzheimer's disease (caffeine blocks the beta-amyloid plaques and tau protein that form in Alzheimer's disease).

Therefore, coffee not only tones the brain, but also protects it, reduces inflammation also due to polyphenols and oxycinnamic acid from roasted coffee.

Everything you need to know about coffee / Photo: Credits

Which is more useful: brewed or espresso

In addition to caffeine and polyphenols, coffee contains two substances — cafestol and kahveol, but mainly in filtered, "brew" coffee, Turkish coffee.

These substances, especially cafestol, acting on certain receptors, disrupts the regulation of cholesterol synthesis.

If you drink such "Turkish" brewed coffee often, it can significantly disrupt cholesterol metabolism.

But the same cafestol reduces the risk of diabetes and has anti-cancer properties.

That's why sometimes you can also "in Turkish".

Separately or with something

Coffee, like tea, contains tannins, especially lightly roasted coffee.

They inhibit the assimilation of iron, therefore, if there is iron deficiency anemia, it is better to avoid coffee or choose strongly roasted coffee after meals containing iron (meat, fish).

Everything you need to know about coffee / Photo: Freepik

To drink or not to drink

If you like coffee, then drink it, but 2-3 times a day and preferably in the first half of the day, in the afternoon, if you want to cheer up, you can drink a glass of weak green tea.

If there is an opportunity to sleep, do it before 3 p.m.

You will significantly extend the period of active work, as if you will have a few more morning hours.

Do not drink at night and take into account the words of Bernard Shaw, who, when his doctor forbade him to drink coffee, saying that it is poison, answered him: "if it is poison, it is a very slow one, because I have been drinking it for 70 years."

Caffeine content:

  • Filtered coffee - 150 ml - 60-180 mg;

    on average - 115 mg

  • Espresso - 30 ml - 30-60 mg

  • Cappuccino - 70-80 mg

  • In a cup of black tea - up to 80 mg

  • In a cup of green tea - 40 mg

Can you drink coffee on an empty stomach?

Our stomach is an organ that can withstand the presence of many different substances, in particular, harmful ones.

The mucous membrane is covered with a layer of protective mucus that protects it from hydrochloric acid, which is needed to digest food.

You don't worry about how hydrochloric acid eats away an empty stomach, do you?

It turned out that even super strong coffee is in no way related to gastritis or ulcers.

Coffee stimulates the formation of hydrochloric acid, but it does not affect the gastric mucosa in any way.

However, for people who have reflux disease (when some of the acidic stomach contents back up into the esophagus), it can cause heartburn.

However, this can also be done: combine coffee with milk.

I would like to add that heartburn in people in whom the sphincter between the esophagus and the stomach does not close (cardiac sphincter) can be caused not only by food returned to the esophagus, but also by any acidic foods, mineral water and simply bending the body.

Everything you need to know about coffee / Photo: Credits

And what about the intestines and other digestive organs?

Coffee accelerates peristalsis, so it is useful for those who have constipation.

It also stimulates the formation of bile (has a mild choleretic effect) and pancreatic secretion.

These properties mean that it improves digestion.

Coffee and diabetes

In studies of people living with diabetes, it was shown that coffee helps to reduce the level of glucose and uric acid, reduces insulin resistance.

In parallel with this, the level of systemic inflammation decreases.

Coffee, liver steatosis, fibrosis and cirrhosis

Drinking coffee has a positive effect on liver function, reduces the deposition of fat in liver cells, which occurs in the case of steatosis (popularly called "fatty liver"), slows down the formation of fibrosis and the progression of cirrhosis.

Coffee and cancer

Reduces the risk of cancer of the oral cavity, larynx, colon (2 cups with caffeine).

The American Cancer Society (ACS) recommends reducing the risk of several types of cancer, including liver, endometrial, oral cavity, throat and larynx cancer, as well as skin cancer (melanoma).

This happens, as I already wrote, due to the presence of biologically active compounds, including alkaloids caffeine and trigonelline, polyphenols, chlorogenic acid.

These substances slow down cell damage, activate genes involved in DNA repair, and inhibit metastasis.

Coffee also reduces the transit time of carcinogens through the intestine.

Coffee and osteoporosis

Caffeine can reduce calcium absorption very slightly (about 4 mg of calcium per cup of coffee), but this can be fully compensated for by adding 1-2 tablespoons of milk to your coffee.

Everything you need to know about coffee / Photo: Credits

Coffee, cardiovascular disease and hypertension (high blood pressure)

Coffee consumption is associated with a lower risk of all-cause mortality from cardiovascular disease, coronary heart disease, and stroke.

Moderate coffee consumption for people who do not have hypertension does not increase, and may even decrease, the risk of developing arterial hypertension.

Moderate coffee consumption (1-3 cups per day) does not adversely affect blood pressure in most people, including those with hypertension.

Increasing consumption above three cups per day was not associated with harm, but the beneficial effect was less pronounced.

Coffee and stress

We know that coffee stimulates the body and the brain.

After drinking a cup of coffee, the body is ready for battle.

It doesn't matter which: physical or mental.

In particular, because coffee stimulates the formation and release of adrenaline into the blood.

And he, in turn, stimulates the flow of blood to the heart and brain, so that decisions are made better and run, if necessary.

Adrenaline does not grow by itself, but in conjunction with cortisol, the hormone of the adrenal glands.

Both of them are also called stress hormones, but it is they who increase stress resistance and help adapt to the situation.

By the way, the level of cortisol is highest in the morning, starting from 6 to 8, when we are full of strength and energy, and closer to lunch, its level drops, as does the level of attention and activity.

Therefore, a cup of coffee in the morning will help increase cortisol.

And you need to stop there, and not stimulate an increase in cortisol in the evening - too much caffeine can cause increased anxiety, nervousness, sleep disturbances, headaches, increased heart rate, increased blood pressure, and heart rhythm disturbances.

Coffee and testosterone

After reading testosterone, women will want to skip it, but take your time: this hormone is present in both men and women, but with a difference in quantity.

So, coffee, in combination with physical activity, increases the level of testosterone, which means that it increases the level of physical endurance during strength and aerobic exercises.

Therefore, it is recommended to drink coffee shortly before classes.

Coffee and epilepsy

Moderate doses of caffeine (1 cup) may benefit patients with epilepsy, while high doses (four cups of coffee per day or more) may increase susceptibility to seizures.

Even more: a meta-analysis indicated that: "coffee/tea consumption is not harmful when consumed at 200 mg (caffeine) at one time (about 2½ cups of coffee) or 400 mg per day (about five cups of coffee )".

Coffee and diarrhea

Beverages containing caffeine have a laxative effect.

More than two or three cups of coffee or tea a day can often cause diarrhea in people who are prone to it.

By the way, black tea contains tannins, substances that slow down intestinal motility, so black tea can be a good alternative to coffee.

Coffee after gallbladder removal

Coffee easily stimulates the formation and secretion of bile, so it is useful after the removal of the gallbladder, because it prevents stagnation of bile in the bile ducts.

Already a week after the operation, you can start drinking weak coffee.

Conclusions

There are many studies that demonstrate the positive and negative effects of caffeine.

It is known that 300 mg of caffeine is the maximum permissible dose, and to be more precise, 4 mg per kilogram of body weight.

But the amount of caffeine that has beneficial and harmful effects can be different for different people.

Some people may metabolize caffeine much faster or more slowly.

Coffee can provide many benefits if you treat it not only as an astringent drink, but also as a medicine.

Let it be 1-2 cups, but a quality drink, and then it will definitely bring only benefit.

Read also:

  • Be careful: coffee every day can prevent you from losing weight

  • Dentists do not approve: why coffee and mulled wine spoil our teeth and how to fight it

  • A blooming garden and a fruitful vegetable garden on coffee grounds: how to use fertilizer from a coffee machine

  • The whole truth about tea: to whom it is useful, and to whom it is contraindicated