New scientific reviews about the health effects of coffee


Riyadh: Dr. Hassan Muhammad Sandakji

In the current July 23 issue of the New England Journal of Medicine, a group of researchers from Harvard Medical School and the Young Lu Lin College of Medicine in Singapore presented the results of their research into the relationship between coffee and caffeine on the one hand and human health. On the other hand, by reviewing about a hundred previous scientific studies on this matter.

Reducing mortality

. This medical review is distinguished by its progress in presenting a number of results that may not be “expected by some” about the health benefits of coffee and its relationship to disease.

The researchers pointed out that a large number of the results of the studies support the presence of health benefits because coffee is not only caffeine, but rather contains other nutrients that have biologically active effects in the body, and it also contains elements that reduce the effects of caffeine in the body, compared to pure caffeine intake.

For example, under the heading “All Causes of Death,” the researchers said: “The consumption of 2 to 5.5 standard cups of coffee per day is associated with a lower mortality rate in studies conducted in different parts of the world, and this is with the consumption of caffeinated and non-caffeinated coffee. The inverse association between coffee consumption and mortality did not differ, whether the elimination of caffeine was rapid or slow. The Standard Cup is known as an 8 fluid ounce or 235ml cup.

The researchers explained that in the past there was medical interest tinged with anxiety and caution, and for a long time, that coffee and caffeine may increase the risk of cancer and cardiovascular disease, but recently, evidence has emerged of health benefits, according to the researchers. They blamed the reason for this because coffee contains hundreds of other bioactive phytochemicals, and modest amounts of magnesium, potassium and vitamin B-3 (niacin).

The benefits of active compounds

. These bioactive compounds in coffee may reduce the repercussions of oxidative stress on tissues and cells of the body, improve the quality, activity and efficacy of friendly gut microbiome, and positively modify the metabolism of glucose and lipid metabolism and direct it in healthy paths Best.

They added: “A large body of evidence indicates that consuming caffeinated coffee (natural coffee) does not increase the risk of cardiovascular disease and cancers. In fact, continuing to consume 3 to 5 cups of coffee per day was associated with a reduced risk of many chronic diseases. However, in the same context, they said, “However, consuming large amounts of caffeine can have various harmful effects, and limits of 400 mg of caffeine per day have been recommended for adults who are not pregnant or breastfeeding and 200 mg per day for pregnant and breastfeeding women.”

The researchers demonstrated the beneficial effects of caffeine in coffee on physical performance and pain, when the recommended daily intake was not exceeded. They reported that caffeine is similar in structure to adenosine compounds, which makes it compete with and hinder the attachment of this substance to brain cells. It is known that the accumulation of adenosine in the brain reduces the level of mental activity and increases sleepiness. By taking moderate doses of caffeine, between 40 and 300 milligrams a day, caffeine can remove the negative effects of adenosine on the brain, reduce fatigue, reduce reaction time and mental response, and increase alertness while performing long-term tasks such as driving a car. Travel.

Caffeine can also contribute to pain relief when added (in an amount of about 100 milligrams) to commonly used pain relievers, according to the results of about 20 medical studies.

In contrast to these positive effects, consuming caffeine late in the day reduces good quality sleep. Anxiety may also occur when consuming more than 400 milligrams of caffeine. However, people vary in having these negative effects, due to genetic considerations and the rates of caffeine removal activity of the body (liver and kidneys), especially in people sensitive to caffeine. Although caffeine stimulates the processes of urination and urine output, this does not usually amount to dehydration.

On the other hand, stopping caffeine after consumption can lead to withdrawal symptoms, including headache, fatigue, decreased alertness and depressed mood, for a total period of 2 to 9 days. This period can be reduced by gradually reducing the amount of caffeine intake before stopping completely.

Blood pressure and heart

Reviewing the results of many medical studies that dealt with aspects of the relationship between coffee and caffeine on the one hand and heart disease, blood pressure and cholesterol on the other hand, it appears that the consumption of caffeine by people who do not usually consume caffeine raises epinephrine levels and raises blood pressure in the short term, but it does happen. A state of “receptivity” for the body to bear this effect within a week in most of these people.

In people who usually drink coffee, consuming pure caffeine (that is, not from coffee) leads to a slight and temporary increase in systolic and diastolic blood pressure. However, no significant effect on blood pressure was found in studies that examined the effect of caffeinated coffee, even in people with already high blood pressure. Medical studies also showed that coffee consumption was not associated with an increased risk of developing high blood pressure. After mentioning these results, the researchers reasoned this by saying: “Perhaps because other components of coffee, such as chlorogenic acid, remove the effect of caffeine in increasing blood pressure.”

As for cardiovascular disease, the results of a review of medical studies reported that: “Studies that examined the relationship of coffee and caffeine consumption to the risk of coronary artery disease and stroke indicate that the results consistently indicate that the consumption of up to 6 standard cups per day of filtered coffee that contains Caffeine, compared to not consuming coffee, is not associated or related to an increased risk of these cardiovascular diseases in the general population or among people who have chronic high blood pressure, diabetes or cardiovascular disease. ”

In fact, the researchers said: “In fact, coffee consumption was associated with a lower risk of cardiovascular disease, with the lowest risk of 3 to 5 cups per day, and an inverse association was observed between increased coffee consumption and a decrease in coronary artery disease, stroke and death due to heart disease. And blood vessels ».


On the other hand, in contrast to these positive effects, the compounds «Cafestol», which is found in unfiltered coffee that is boiled with water, Boiled coffee, increases cholesterol levels in the blood. Several previous studies, from Finland and elsewhere, have shown that regular consumption of coffee that is boiled with water increases the level of cholesterol in the blood as a result of its containment of cafestol compounds, which are medically known to stimulate cholesterol production in the body, while drinking coffee Filtered does not increase blood cholesterol. Thus, as the researchers said, “the results of research and studies on coffee and other dietary sources of caffeine should be interpreted with caution, because the potential negative effects may not be due to the caffeine itself.”

The researchers explained that the high concentration of cafestol in unfiltered coffee, such as pressed coffee with French coffee, Turkish coffee, Scandinavian boiled coffee, or any other type of boiled coffee, is what needs attention. The researchers said: “The cavestol compound in unfiltered coffee is a cholesterol-raising compound. According to the results of studies, an average of 6 cups of unfiltered coffee is associated with an increase in the level of light-density lipoprotein (LDL) cholesterol by 17 percent. The results of medical studies also reported that compared to consuming filtered coffee, drinking unfiltered coffee is associated with an 11 percent higher risk of developing cardiovascular disease.

“Thus, limiting the consumption of unfiltered coffee and moderate consumption of espresso-based coffee (filtered) may help control cholesterol levels,” the researchers concluded.

And in the April 27 issue of Your Health Supplement in the Middle East, the results of a study assessing the relationship of coffee and tea containing caffeine to arrhythmia disorders were presented. Reach it until this moment ». In it, a detailed review of published studies was presented to identify the interactions between coffee and tea and heart rhythm disturbances. The title of the study was: “Caffeine and Heart Rhythm Disorders: Time to Crush the Evidence.”

She explained that people who drink caffeinated coffee in a moderate amount may be less likely to suffer from arrhythmias, because they may contain natural substances with long-acting anti-arrhythmic properties, such as antioxidants and other elements related to receptors. Adenosine antagonism in cardiac cells. But the researchers stressed the need to review the doctor who monitors the condition of the person suffering from any type of heart rhythm disorder, to determine the appropriateness of consuming coffee and caffeine. They also stressed that consuming energy drinks that contain high levels of caffeine is not appropriate for anyone with heart disease.

Caffeine … Various drinks according to age

> By reviewing the caffeine content of a number of drinks and foods, we find that a 350-milliliter cup of coffee has 235 milligrams of caffeine. About 30ml of espresso has 63mg. A 240-milliliter cup of Americano coffee contains 150 milligrams of it.

There is 47 milligrams of caffeine in a 240 milliliter cup of tea, and 28 milligrams of it in an same-sized cup of green tea. The amount of caffeine varies in different types of soft drinks and different types of energy drinks. A bar of dark chocolate contains 14 milligrams of caffeine, while 6 milligrams of it are found in milk chocolate. And in the most common types of headache pain medications, the amount of caffeine is about 65 milligrams.

The researchers reported that by reviewing the report on sources of caffeine in American society, coffee accounts for 25 percent of the source of caffeine intake, soft drinks 33 percent, tea 28 percent, and the rest from foods and energy drinks, in people between the ages of 15 and 19 years . Among people between the ages of 35 and 50, coffee accounts for 65% of the source of caffeine intake, soft drinks 16%, tea 16%, and the rest from foods and energy drinks. This is what the researchers commented by saying: “Coffee and tea have been consumed for hundreds of years and have become an important part of cultural traditions and social life, in addition to people using coffee drinks to increase mental alertness and work productivity. In the United States, 85 percent of adults consume caffeine daily, and the average caffeine consumption is 135 milligrams a day, which equates to about a standard cup and a half of coffee. Coffee is the predominant source of caffeine consumed by adults, while soft drinks and tea are more important sources of caffeine for teenagers.

– Caffeine … natural sources and stages in the body’s handling of it

> The researchers stated at the beginning of their study results that coffee and tea are among the most common drinks around the world and contain quantities of caffeine, which makes caffeine a “psychoactive agent” Most widely consumed in the world. Caffeine is also found in a variety of seeds, fruits, and leaves of a number of plants, such as cocoa beans (an ingredient in chocolate), yerba matte leaves (used to make herbal tea), and guarana berries (used in a number of different drinks and supplements). It is noteworthy, and according to what scientific sources indicate, that caffeine has a role in the growth and safety of these plants, as it works in plants as a natural pesticide with neurological effects, and it can paralyze and kill predatory insects that feed on plants.

In addition to these plant-based products, caffeine can be manufactured and added to foods and beverages, including soft drinks and energy drinks, and it is also widely used medicinally in painkillers.

For this matter, a number of medical sources confirm that the caffeine compound is the highest used “drug” in the world, whether from natural products such as coffee or tea, or from manufactured products such as soft drinks and common painkillers.

And caffeine in terms of chemical structure, is a class of compounds «methylxanthine» Methylxanthine.

After ingestion, the absorption of caffeine begins in the intestine within 15 minutes, and is completed within 45 minutes, and the effect lasts up to two hours. To be clear, caffeine is processed in the liver by a system of enzymes, eventually converting from the active substance caffeine to uric acid, which is excreted in the urine.

And the “half-life” of caffeine in adults ranges from two and a half hours to four and a half hours, on average. Half life is a scientific term that means the amount of time during which a substance loses half of the strength of its activity, potency and vital effects on the body, as a result of its gradually decreasing concentration in the body. That is, the time during which half of the substance is dissolved or excreted from the body.

There are a number of factors that either speed up or slow the elimination processes of caffeine. Including smoking, which speeds up the activity of the processes of breaking down and excreting caffeine by 50 percent, while taking contraceptives slows those processes, and thus increases the lifetime of caffeine in the body by twice. As is the case with pregnancy, especially in the third trimester, the half-life of caffeine may reach 15 hours. In newborns, the half-life of caffeine usually reaches 80 hours. So people who have slow elimination of caffeine tend to reduce their intake.


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