What are the benefits and harms of coffee — 14 facts about the effect on the human body

Coffee is one of the most popular drinks in the world, which is constantly consumed by over 70% of the world's population.

The effect of coffee on the body is due to the high content of antioxidants and other important substances (vitamins, macro- and microelements, theobromine). According to research, coffee drinkers have a lower risk of mortality from cardiovascular, oncological and other diseases.

In this article, we will look at the scientific facts about the benefits of coffee and its possible harm to health.

14 useful properties

Below are 14 scientifically proven beneficial properties of natural coffee for the human body.

1. Improves brain function

According to experimental data spent in the UK, coffee improves overall performance and feeling of cheerfulness at any time of the day. As a result, labor productivity increases, and the quality of tasks performed improves.

Proven that cognitive functions improve against the background of regular consumption of the drink ( memory , attention, thinking), the rate of transmission of nerve impulses at the brain level is normalized.

According to research data , coffee also improves mood and an interest in performing any kind of work activity.

The described effects are realized due to the content of sufficiently high doses of the psychoactive component – caffeine. Proven that caffeine easily penetrates the blood-brain barrier and has an effect directly at the brain level. Caffeine is delivered to neurocytes by means of special carrier molecules, as well as by simple diffusion.

In the central parts of the nervous system, coffee blocks a number of neutrotransmitters (adenosine, dopamine, norepinephrine) that have an inhibitory effect on the brain. As a result, the work of the brain is activated.

14 more facts about the effect of coffee on the nervous system can be found here →

2. Helps to lose weight

Caffeine activates the breakdown of adipose tissue cells. That is why it is included in most modern dietary supplements designed for weight loss.

University of London Scientists installed that coffee increases the activity of general metabolism by 4%, improves thermogenesis and increases energy consumption by 10-11%, which causes the breakdown of adipose tissue cells and a decrease in body weight.

Swiss scientists proved that coffee increases the efficiency of fat burning by about 10% in obese people and by 26% in people with normal or low body weight.

Currently, the exact effect of caffeine on adipose tissue metabolism has not been fully studied. It is assumed that the effect is realized only with prolonged systematic consumption of the drink (at least 1 cup per day for 2 months or more).

3. Increases endurance and performance

As already mentioned, caffeine is a biological stimulant of the central nervous system, which Improves performance .

According to experts, coffee increases the concentration of adrenaline in the blood for several hours from the moment of consumption, while it does not significantly affect the metabolism of carbohydrates. Adrenaline helps to improve the functioning of skeletal muscles by increasing the delivery of oxygen and the rate of expenditure of energy reserves.

Scientists claim that due to the breakdown of fat deposits, coffee releases a large amount of fatty acids to the cells of the body, which are consumed as an energy source (biological fuel).

British studies show that endurance and performance within 3 hours after drinking coffee increase by 12.3% and 11%, respectively. Many nutritionists even recommend drinking a drink before scheduled workouts (30 minutes before active training).

4. Prevents the development of type II diabetes mellitus

Diabetes mellitus is one of the most common diseases in the world.

People who consume at least 1 cup of coffee per day on a regular basis have a decrease in the incidence of type II diabetes mellitus.

One of the American studies discovered that 4 cups of coffee per day reduce the risk of developing this disease by 30%, 1 cup per day – by 14%.

Similar results received scientists from the Netherlands. However, according to their data, the incidence of type II diabetes mellitus decreases by about 65% when 4-6 cups of coffee are added to the diet every day.

5. Reduces the risk of senile dementia and Alzheimer's disease

Alzheimer's disease is a common degenerative disease of the cerebral hemispheres. It leads to the development of dementia, premature loss ability to work and social maladjustment. Almost every person over the age of 65 is at risk (according to some data, over 55 years old).

It is quite possible to prevent the development of Alzheimer's disease by leading a healthy lifestyle with proper nutrition and regular physical activity.

Coffee has a separate role. Foreign research show that regular consumption of the drink leads to a decrease in the risk of developing this disease.

6. Reduces the risk of Parkinson's disease

Parkinson's disease is a severe degenerative neurological disease affecting the extrapyramidal system, leading to a variety of disorders: tremor, rigidity and hypokinesia of muscles, postural instability, etc. Persons suffering from a late stage of this pathology practically lose the ability to self–care and movement.

There are currently no treatment methods (only symptomatic correction), so research is being conducted worldwide on the prevention of Parkinson's disease.

According to the data American scientists, a high level of coffee consumption (3-4 cups per day) significantly reduces the incidence of this disease. At the same time, the positive effect of coffee does not decrease due to improper diet and bad habits (smoking).

Employees of the Harvard School of Public Health installed that the effect of the drink is related specifically to caffeine, as in people who consume Decaf coffee , there was no decrease in the incidence of Parkinson's disease.

7. Improves liver health

The liver performs many life-supporting tasks: from protein synthesis and hormones to the disposal of toxic substances. Critical liver failure leads to death.

Unfortunately, there are many diseases (hepatitis of viral and alcoholic etiology, fatty hepatosis, hemochromatosis, etc.) that lead to the development of cirrhosis – the replacement of liver cells with scar tissue that does not perform any functions.

According to the data of the U.S. Department of Health, regular coffee consumption (from 1 to 4 cups per day) reduces the risk of liver cirrhosis by 20-80%, slows down the destruction of hepatocytes (in the presence of destructive liver diseases). At the same time, the greatest positive effect is noted in relation to cirrhosis caused by alcohol abuse .

Italian scientists claim that only coffee has a hepatoprotective effect, but not other drinks that contain caffeine.

6 more facts about the effect of coffee on the liver see in a separate article.

8. Effective for the prevention of depression

Depression, from the standpoint of modern psychiatry, &8212; severe pathology that reduces the quality of life and increases the risk of suicide. The disorder is observed in 4-5% of the world's population.

Recent scientific evidence indicates that coffee is good for depression . For example, proven that 4 cups of drink per day for 1 month reduces the severity of depression by 20%.

Incredibly, the same amount of coffee leads to a 53% reduction in the likelihood of suicide. Such data cite American scientists who conducted a major study that lasted 10 years and in which over 200,000 people participated.

9. Has an anti-cancer effect

Oncological diseases occupy leading positions in terms of prevalence and mortality worldwide.

According to separate studies, coffee helps to prevent malignant cell proliferation in the human body.

Proven that an invigorating drink reduces the risk of liver cancer by 43% (when drinking 2 cups a day).

Foreign experts installed reducing the likelihood of developing colorectal cancer by 15% when consuming 4-5 cups per day. At the same time, the drink mainly reduces the risk of malignant damage to the rectum.

According to the data of Yale University (USA), coffee also prevents the appearance of melanoma – the most dangerous (due to the early onset of metastasis) of the tumor. There is a 20% reduction in the risk of developing melanoma.

Antitumor effects probably prevent malignant degeneration of cells and other organs, however, no major studies have been conducted on this hypothesis.

10. Prevents cardiovascular diseases

For a long time it was believed that coffee increases blood pressure, and high blood pressure, in turn, is one of the main causes of stroke in pathogenetic terms.

However, recent scientific work show that caffeine increases blood pressure slightly (by only 3-4 mmHg), and in people who consume coffee on a regular basis, this action is not observed at all. Such data lead to Italian scientists.

Also missing evidence of an increased risk of cardiovascular disease when taking an invigorating drink.

According to research data, coffee prevents the occurrence of coronary heart disease and myocardial infarction. The positive effect is more pronounced in men than in women.

Japanese scientists recorded reducing the likelihood of stroke by 20% when taking 2 to 4 cups of coffee a day. Green tea also has a protective effect due to the content of caffeine and many antioxidant components.

11. Reduces the formation of gallstones

Employees of the Department of Nutrition (USA) found that taking 2-3 cups of coffee a day reduces the likelihood of clinically pronounced gallstone disease.

The drink has several metabolic effects that inhibit the formation of gallstones by changing the secretion of bile acids and increasing the tone of the smooth muscles of the walls of the organ, which leads to accelerated excretion of already formed concretions that have not yet reached a critical size.

Large stones &171;get stuck &187; in the lumen of the biliary tract, obstructing them, and provoke the appearance of mechanical jaundice.

Cholelithiasis is most often found in men aged 40 to 75 years and is very dangerous due to complications caused by surgery.

12. It is a rich source of antioxidants

Recent scientific experiments demonstrate that many people get the bulk of antioxidants by drinking coffee, not vegetables and fruits.

For example, Spanish scientists claim that a person who regularly drinks coffee gets 16% vitamin E and more than 22% vitamin C. Similar results shown the works of Norwegian experts.

Antioxidants are extremely important for the well-coordinated work of the whole body. They regulate metabolism, improve the trophism of all tissues, prevent premature aging and cell destruction, as well as a number of malignant diseases.

13. Slows down the synthesis of uric acid

For a long time it was believed that coffee delays uric acid in the body, which increases the likelihood of developing gout (severe damage to the articular apparatus) and urolithiasis.

However, recent research demonstrate that the drink, on the contrary, accelerates the excretion of uric acid and slows down its formation.

Pharmacological action is provided by inhibition of the enzyme xanthine oxidase, which is responsible for the "transfer" of xanthine into uric acid and its subsequent accumulation in the body.

Excess uric acid contributes to the early development of hypertension, gout, urolithiasis and type II diabetes mellitus. Therefore, coffee is a non-specific method of preventing the described deviations.

Italian scientists note that in 89% of cases hypertension is accompanied by an increase in the concentration of uric acid in blood plasma. With a decrease in the content of this metabolite, a decrease in blood pressure is observed.

14. Increases life expectancy

Coffee, as described above, is a means of preventing many diseases that occupy leading positions in terms of mortality rates worldwide (hypertension, myocardial infarction, type II diabetes mellitus, malignant neoplasms, etc.).

Preventing these diseases not only improves the quality of life, but also reduces overall mortality in the population.

Foreign researchers installed that the systematic consumption of coffee reduces the risk of mortality by 20% in men and by 26% in women.

Also a drink improves clinical course of the diseases described above, improving the prognosis. For example, taking an invigorating drink against the background of diabetes mellitus 2 is associated with a lower (30%) risk of death.

Daily rate

The "average" safe dose (in terms of caffeine) is 400 milligrams of caffeine per day, which corresponds to 6 teaspoons instant coffee or 4 teaspoons of natural grain (ground) coffee. That's about 4 cups a day.

For pregnant women and people who abuse smoking, the recommended daily dose is 200 milligrams of caffeine (3 teaspoons of instant or 2 teaspoons of natural coffee beans; 2 cups of ready-made drink).

The World Health Organization (WHO) recommends drinking 3-4 cups of coffee per day, provided that other caffeinated products (chocolate, tea, etc.) are completely excluded from the diet.

It is important to keep in mind that it is difficult to significantly harm the body by abusing coffee, since the lethal dose is about 200 cups per day.

Contraindications and harms

As mentioned above, coffee is a unique drink that has many medicinal properties.

However, if there are contraindications or excessive use, undesirable effects may occur (some reactions occur even at "standard" dosages):

1. Increased risk of developing cardiovascular diseases. Employees of Wageningen University (Netherlands) recorded increased concentration of homocysteine during coffee abuse. Homocysteine has a negative effect on the overall cardiovascular morbidity.
2. Sleep disturbance and general anxiety. Excessive coffee consumption leads to the development of neuroses , provokes panic attacks. It is also characterized by a change in the rhythmicity of sleep phases, which manifests itself in shallow sleep, rapid awakening from exposure to weak stimuli. You should not drink caffeinated drinks in the evening or at night, it is better to take them in the morning, but after eating (breakfast), and not on an empty stomach.
3. The emergence of addiction and addiction. With regular use of coffee, the severity of its effect on the central nervous system decreases, which forces a person to take more and more of the drink to obtain a similar effect. It is noteworthy that abstaining from the product for a week completely negates this property. Development is possible Coffee addiction . Cases of withdrawal syndrome have been described, which is manifested by irritability, headaches, general exhaustion, fog in the eyes and other disorders. A number of American scientists even recommend consider this condition as a separate disease in psychiatry.
4. Increased risk of heart attack. This circumstance applies only to unfiltered coffee, when consumed is celebrated negative change in the lipid profile (increase in total cholesterol, triacylglycerides and markers of inflammation), leading to atherosclerotic damage to the coronary vessels that supply heart muscle and the development of myocardial infarction. About, which type of coffee is healthier , read in a separate article.

The effects of coffee on the human body also have many features that need to be taken into account:

1. Nicotine accelerates the metabolism of coffee.  According to scientists , when smoking, the metabolism of caffeine in the body accelerates by 30-50%, which increases the importance of the biological effects of the drink.
2. Caffeine is harmful to individuals with certain genetic defects. Caffeine is normally metabolized in the liver with the help of the cytochrome P450 1A enzyme. In some people, a genetically determined defect of this enzyme is observed, as a result of which the absorption and excretion of caffeine increases 4-6 times. Drinking 5 cups of coffee against the background of the described condition increases the risk of myocardial infarction by 60%, and also contributes to the appearance of hypertension and type II diabetes mellitus.
3. Is incompatible with oral contraceptives. When taking such drugs, inhibition of the cytochrome P450 1A2 enzyme is observed, which increases the time of exposure to coffee on the body. This effect proven .
4. Is incompatible with fluvoxamine. An antidepressant, similar to oral contraceptives, inhibits the activity of cytochrome P450 1A2. Against the background of joint intake, there is an increase in the half-life of caffeine by 11 times (up to 56 hours).
5. Iron deficiency reduces the activity of xanthine oxidase. Coffee also reduces the work of this enzyme, which can lead to a dangerous decrease in the content of uric acid in the blood.
6. Caffeine helps to increase intraocular pressure. Therefore, the drink is categorically contraindicated in patients with glaucoma. Effect proven .
7. Caffeine accumulates in severe degenerative liver diseases (clinically pronounced cirrhosis). With an increase in such indicators as ALT and AST in the biochemical blood test by more than 2 times, coffee is contraindicated. This effect is also proven .

It is not recommended to drink coffee in the following conditions:

1. Any sleep disorders.
2. Unstable arterial hypertension and stage III hypertension. In these conditions, there is even a slight increase in blood pressure (1-2 mmHg). it can be fatal.
3. Glaucoma.
4. Liver diseases with a decrease in its functional activity.
5. Taking oral contraceptives.
6. Iron deficiency anemia (laboratory confirmed).
7. Pregnancy and breastfeeding.
8. Smoking (the dose of coffee should be reduced at least 2 times).
9. Disorders of the mental sphere (hysterical neurosis, obsessive-compulsive syndrome, etc.).

How to take it correctly?

A number of recommendations should be followed in order to enjoy coffee without harm to health:

1. Consume it in its pure form. The addition of milk or sugar has a negative effect on the beneficial effects. If it is impossible to give up "sweet", preference should be given to natural sugar substitutes (stevia).
2. Use only filtered drink. Unfiltered coffee increases the risk of atherosclerosis and myocardial infarction.
3. Take in the morning. Coffee is a natural stimulant of any biological system, it promotes eliminate fatigue , increased vigor and physical activity. Drinking a drink later than 2-4 hours before bedtime can lead to various sleep disorders.
4. Emphasis on quality. Use only natural coffee beans. It is also necessary to give preference to organic coffee, which is grown without the use of pesticides and chemicals. The latter have many negative effects: from intoxication to stimulation of malignant cell degeneration. Unfortunately, most common and cheap brands use chemical additives to accelerate grain cultivation and increase yields.
5. Compliance with the norm. As already mentioned, 4 cups a day is a critically important feature that cannot be crossed.
6. Adding cinnamon. Cinnamon is a fragrant and delicious seasoning, which is a suitable additive. It has a hypolipidemic and hypocholesterolemic effect.
7. Adding cocoa. Cocoa beans are rich in antioxidants that reduce the risk of developing cardiovascular diseases.
8. Using a paper filter. Brewed coffee may contain a special substance – diterpene, which increases the level of total cholesterol , as well as low-density lipoproteins in the blood. When coffee passes through a paper filter, this component is almost completely delayed.

Conclusion

Thus, coffee is a unique drink with a wide range of useful qualities. It improves the health of the cardiovascular, endocrine, central nervous, musculoskeletal and other body systems, as well as prevents the development of malignant neoplasms.

Taking into account possible side effects and contraindications, the drink can be considered completely safe for a healthy person. It is recommended to be consumed in its pure form without the use of any additives (except cinnamon and cocoa) and without sugar. If there are doubts about safety, it is recommended to consult a doctor.