A universal drink synonymous with pleasure and a concentration aid for many, coffee is often the subject of sometimes contradictory studies. So coffee, good or bad for your health?
” I can’t start the day without my morning coffee .” ” It helps me concentrate .” ” Since I read that coffee contains antioxidants, I don’t hesitate to drink it “… Knowing that every second, 255 kilos of coffee are consumed around the world, it is essential to ask the question: is our favorite black nectar good or bad for your health, and how much truth do we have in our beliefs about its supposed virtues?
Coffee: its effects on health
Pleasure drink, addictive, convivial: this beverage is consumed in the morning, at noon, in the afternoon, and even in the evening for some. It is so popular that many scientists have studied the health effects of coffee.
Composition of coffee
Coffee contains caffeine of course, but also phenolic acids (antioxidant), potassium, magnesium, phosphorus… Taken without sugar, coffee is low in calories (about 2 calories per cup), which does not mean that should be consumed without restriction.
According to a recent study published in the medical journal JAMA, drinking coffee could increase life expectancy, whether you drink one or eight cups a day (6)!
This suggests that caffeine is not linked to this reduction in the mortality rate: it is not caffeine that is good for your health, but another element present in the cup, which has not yet been highlighted.
Effects of coffee on the heart and health: “it depends”
It’s no longer a secret that caffeine plays the effect of a stimulant on the body, increasing the heart rate. That being said, for many years, studies have succeeded in demonstrating both the positive effects of caffeine on the heart and the negative effects. Today, it appears that the positive or harmful effects of coffee vary according to individual.
First of all, it all depends on consumption. Since coffee is a stimulant, it should not be abused. In addition, the state of health of individuals who drink coffee must be taken into account to determine its effect: coffee can increase the risk of cardiovascular accidents if it is overconsumed, especially if the person who consumes coffee is a smoker, overweight, suffers from cholesterol or hypertension, all risk factors.
Coffee and risk factors for the heart: a question of genetics
Several scientists explain that we cannot directly make the link between caffeine and heart attacks, and although the drink would have the effect of putting on alert the markers of inflammation of the heart because no cohort has really been organized taking into account all the environmental data of the individuals observed.
Finally, one of the latest major studies on the subject comes from Canadian researchers at the University of Toronto. Pr. Ahmed El -Sohemy of the Department of Nutritional Sciences in Toronto has managed to demonstrate that we are not all equal when it comes to caffeine, due to our individual genetic heritage.
Indeed, researchers have studied several thousand subjects, with the aim of observing how coffee is transformed in our bodies thanks to a specific enzyme.
This enzyme can take two forms depending on the genetic profile of each and have two effects:
- quickly break down coffee in the body
- or on the contrary, favor a slow degradation
Thus, people who eliminate coffee quickly see their risk of heart attack decrease by 22% for drinkers of two to three cups daily, while for individuals who degrade the drink too slowly, the risk of heart attack is multiplied. by 1.35%.
Coffee, by increasing the heart rate, can be a problem if you suffer from arrhythmia or other heart problems. We are therefore not equal when it comes to coffee, it all depends on our DNA and our state of health.
Avoid energy drinks: up to 500 mg of caffeine
“ Nutritional advice is tricky to give, because many things – like coffee – can be bad for some health conditions and some individuals, but good for others when consumed in moderation,” explains Prof. El-Sohemy.
However, he specifically warns against energy drinks: “ The high caffeine concentrations in these products, which also tend to be very high in sugar, have absolutely no health benefits .”
Marketing promoting these beverages is increasingly directed at younger populations. According to Ahmed El-Sohemy, “ Manufacturers of these energy drinks are increasingly pushing the limits in terms of caffeine concentration. Some have as much as 500 milligrams per can. In comparison, a can of cola contains 34 mg and a large cup of coffee 80 to 100 mg ”.
Coffee, brain, and alertness
When you consume coffee, you are actually consuming caffeine. This caffeine passes into the blood, then crosses the ” blood-brain ” barrier until it settles on receptors acting on several groups of neurons, receptors normally responsible for receiving adenosine, which has the role in particular of regulating the cycles of wakefulness and sleep, also acting on alertness.
Coffee to focus
Caffeine is found in coffee of course, but also in chocolate or sodas. The consumption of caffeine thus makes it possible to remain in a state of vigilance longer, while delaying the feelings of fatigue.
Coffee drinkers thus explain that they have the impression of “ thinking more quickly ” after drinking a coffee, of succeeding in being more concentrated.
However, if coffee is the favorite drink of students who revise at the last minute in the night for their exams, caffeine does not help with better memorization. On sensitive people, or following too much coffee consumption, caffeine can make you more sensitive to stress, more aggressive, and nervous.
Too much caffeine can also result in tremors. Caffeine would also have the effect of reducing the intensity of migraines and could even optimize the effects of aspirin in the event of a headache.
Coffee and cancer: studies to be taken with a grain of salt
Coffee may have protective effects against certain cancers. In any case, this is what several studies tend to show.
Coffee and colon cancer
For many years, it was thought that heavy coffee consumption could prevent the risk of colon cancer. However, recent studies claim the opposite. Several researchers have thus carried out studies on a large number of subjects and have concluded that the consumption of coffee would not influence this type of cancer.
Coffee and breast cancer
One of the recent studies published in the journal Breast Cancer Research would have concluded that coffee has a beneficial effect on the prevention of breast cancer.
Thus, after questioning more than 6,000 women already in menopause about their coffee consumption, the Karolinska Institute concluded that drinking more than five cups of coffee a day could reduce the risk of suffering from an aggressive form of breast cancer.
These results were confirmed by a second German study. But the scientific community remains skeptical of these results, calling for studies on a larger number of women.
Coffee and skin cancer
By studying a group of mice, American researchers have succeeded in demonstrating the protective effects of coffee on the skin.
Thus, researchers at the University of Washington explain that after having reduced the quantity of the ATR protein responsible for the multiplication of cells damaged by the sun, in the skin of mice and having exposed the rodents to ultraviolet rays, the latter developed tumors later than the untreated control group.
Caffeine would have the effect of inhibiting the ATR protein. The study continued for several weeks, and it appeared that the group of mice whose DNA had been modified to develop less ATR had significantly fewer skin tumors (-69% compared to the control group) as well as 4 times fewer aggressive skin cancers. Caffeine could therefore have a protective effect against ultraviolet rays.
Rich in antioxidants, coffee may also have protective effects against liver cancer.
Coffee and Parkinson’s disease
What about the relationship between coffee, cholesterol, diabetes, or even Parkinson’s disease? Once again, the studies are numerous and sometimes promising.
Coffee consumption: a hope for Parkinson’s patients
Parkinson’s disease is a degenerative disease that causes stiffness in the limbs and slow movements, loss of balance, difficulty in performing certain movements, and tremors. At the origin of the disease, is a lack of dopamine, a chemical substance responsible in particular for controlling movements.
However, coffee would increase the production of dopamine and thus reduce the risk of developing Parkinson’s disease in men. In any case, this is demonstrated by several studies that have been particularly studied by the scientific community.
However, while some belief in the relationship between coffee and reduced risk of developing Parkinson’s disease in men, studies do not allow us to make the same observation with the female population.
Coffee and cholesterol
Cholesterol sufferers are often advised to slow down or limit their coffee consumption, due to the very composition of coffee, which contains cafestol.
But cafestol is a molecule that would have the effect of raising the level of bad cholesterol in the blood. But studies on the subject have shown that the negative effects of coffee on cholesterol would be effective in those who consume a lot of coffee.
A very black coffee to fight diabetes
For more than ten years, researchers have studied the habits of nearly 70,000 French women who did not suffer from diabetes, all aged 41 to 72 at the start of the study.
Finally, 1,415 of them developed diabetes during the 11 years that the study lasted. The researchers then observed the beverages they drank, tea, coffee, café au lait, and chicory, and observed that women who regularly drank a small cup of black coffee after meals suffered less from diabetes.
This result could be explained by the presence of chlorogenic acids in the coffee beans, acids which would reduce the glycemic load of a meal, hence the effectiveness of black coffee after lunch, often the heaviest…
Another explanation puts forward the role of an antioxidant substance called lignan, assuming that antioxidants, in general, would have an antidiabetic effect.
Children and pregnant women: beware of coffee!
Some populations are more sensitive to food, to the substances that we ingest. Women in general, and pregnant women in particular, must be particularly vigilant. And, of course, the children.
women and caffeine
Two studies would have made it possible to highlight a positive link between coffee consumption in women and AVC (Cerebrovascular accident).
Thus, the AHA (American Heart Association) published a study carried out by the Karolinska Institute in Sweden which would show that women consuming a cup of coffee daily would see the risk of suffering from a stroke decrease by nearly 25 %. But the mechanisms of this effect are not yet known.
Another study conducted among 83,000 women aged around 55 would also have made it possible to make the link between regular coffee consumption and a reduced risk of stroke.
Pregnant women: limit coffee intake
When a woman is pregnant, many instructions are given to her concerning her lifestyle and diet. Several alarmist studies would have made the link between too much coffee consumption, and an increased risk of miscarriage or stillbirth.
Other research shows that too much coffee consumption could have a negative impact on the heart rate of the fetus which would become too fast or irregular. Finally, it is recommended to limit caffeine intake (caffeine being present as a reminder, in coffee, tea, chocolate, and sodas) in order to avoid any risk.
If coffee is a real pleasure for you, you have the right to drink a cup of coffee, the idea being not to multiply them. Especially since coffee can sometimes cause bloating and nausea!
Caffeine and children: beware of overdose
We don’t always realize it, but between sodas, chocolate, tea, coffee… Caffeine is much more present in our daily lives than we think. As a result, even though children generally don’t like coffee because of its strong, bitter taste, they regularly consume caffeine, and often more than they should.
As a result, it is not uncommon, as a study published in the Journal of Pediatrics points out, to find that in the United States, the dose of caffeine ingested by children is much higher than the maximum recommended daily dose which is 45 mg/day before 7 years, and 85 mg/day before 12 years. Beyond that, children may show signs of hyper-arousal and sleep disorders that will harm their development.
In addition, we know that caffeine can have the effect of increasing blood pressure and causing an irregular heartbeat, which is already not good for adults, let alone for children.
In the most fragile, overconsumption of caffeine can result in constant nervousness, certain irritability as well as concentration problems if the overconsumption is irregular and the child is unable to readapt his sleep-wake rhythm.
In addition, caffeine is blamed for causing a loss of calcium through the urine. This loss would be of no consequence in adults if they regularly consume products rich in calcium, but this can pose more problems in children who are in a period of growth.
Also in postmenopausal women, by increasing the urinary elimination of calcium, coffee could increase the risk of osteoporosis.
In the end: is coffee good or bad for your health?
Like many things, coffee is a drink to be consumed in moderation. If doctors agree that a glass of red wine a day is good for the heart, this does not mean that you have to drink the whole bottle, the same for coffee!
Numerous studies reveal new advantages to coffee every year, as well as new disadvantages to the drink, the idea is that it should not be consumed in excess.
You like to drink coffee in the morning to wake you up and coffee after lunch to help you digest and get you started in the second part of the day: no problem. But there is no need to drink two liters of this dark drink just because you love it.
Concerning sensitive people such as children and pregnant women, extra vigilance is required. Ladies who are expecting a child, limit yourself to one or two cups a day. For parents, watch your children’s diet, caffeine is also hidden in chocolate and sodas.
Also, note that coffee is not recommended for people suffering from gastric ulcers because of its stimulating effect on acid secretion.