Coffee is bad for the heart, but good for the brain? Research disagrees. However, a recent study refutes the assumption that coffee promotes cardiac arrhythmias. The opposite is even the case – as long as a maximum amount is not exceeded.
The Germans love tradition: we prefer to drink our pick-me-up as filter coffee, and we sip an average of 162 liters a year. This makes coffee our absolute favorite drink. But should we really be drinking that much coffee? Many have a bad conscience about their health. The conviction that the caffeinated beans are a strain on the heart and a risk factor for heart attacks and strokes is too deep-seated.
Coffeeholics should therefore be particularly pleased about the latest findings: Studies confirm that the hot drink has a much more positive effect on the brain, metabolism and even on the heart and circulatory system. A recent example: a study by researchers at the University of California, San Francisco.
According to this, coffee does not increase the risk of cardiac arrhythmias, as is often assumed – in the study of 386,000 test persons, each additional cup to the usual amount reduced the risk of such a dangerous out-of-beat heart rate by as much as three percent.
It’s not a free ticket for endless coffee. Because as with everything: the amount makes the poison – or the positive effect. In addition, not everyone can tolerate the black brew and its active ingredients, especially caffeine and chlorogenic acid. This doesn’t just apply to children, who don’t like the bitter brew anyway. Some adults are not genetically equipped to enjoy coffee.
In most cases, however, it is a question of quantity whether coffee triggers heart palpitations or stomach pains. Quality also plays a role: Those who pay attention to high-quality beans not only score points in terms of taste.
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However, many studies have already shown that coffee can be beneficial to health. In 2017, scientists from the University of Edinburgh published the results of 201 overview studies on coffee and health in the “British Medical Journal”. Overall, they found 19 positive effects on health. In contrast, there were only six negative effects.
According to the study, “Roasted coffee is a complex mixture of over 1,000 bioactive compounds with potentially therapeutic, antioxidant, anti-inflammatory and anti-cancer effects.” That sounds a lot more positive than the chilling myths that have been circulated about coffee.
Coffee is a stimulant for body and mind. Because: On the one hand, caffeine constricts the vessels, the heart has to pump the blood with more pressure, the brain and the rest of the body are optimally supplied with blood. On the other hand, caffeine blocks the neurotransmitter adenosine in the brain, which makes you sleepy.
However, neuroscientist Steven Miller from Maryland believes that drinking coffee at the wrong time does not have the stimulating effect. If the cortisol level in the body and thus the natural level of alertness is at its highest between eight and nine in the morning, for example, caffeine can do little. It’s similar between 12 and 1 p.m. and 5:30 and 6:30 p.m., Miller says. The ideal time for a stimulating cup of coffee is therefore in the morning between 9.30 and 11.30 a.m.
The European Food Safety Authority states that 400 milligrams of caffeine a day is completely safe when it comes to our health. A 100 milliliter cup of coffee contains between 50 and 60 milligrams.
Positive coffee effects are highest with three to four cups. Larger amounts harm very few people, but they also bring no further benefit. This summary should make some people happy. After all, several cups of coffee a day are the order of the day for many people.
Even decaffeinated coffee develops a positive effect, albeit much weaker. This is due to the antioxidants contained in coffee, above all the chlorogenic acids. They add flavor but are also extremely effective against free radicals.
Nevertheless, not everyone should consume coffee without hesitation. Studies suggest that the heart risk from coffee is much lower than has long been attributed to the coffee bean infusion. Coffee consumption seems to have little effect on blood pressure. However, the results of the individual studies are not uniform.
In general, a 2019 review article by US researchers in the Journal of the American Heart Association concluded that coffee does not increase the risk of heart disease. But does that really apply to everyone?
More about coffee and health:
Australian researchers looked at data from around 350,000 people aged 37 to 73 in 2019 and found that too much caffeine does become a heart risk. “Six cups is the tipping point at which coffee has a negative impact on cardiovascular disease risk,” the authors write in the American Journal of Clinical Nutrition.
A meta-study conducted at Harvard with a total of almost 1.3 million participants came to a similar conclusion: people who drank between three and four cups of coffee a day had the lowest risk of suffering from cardiovascular disease. Anyone who consumed five or more cups of coffee a day had an increased risk. But by far the greatest risk of developing cardiovascular disease was in people who didn’t drink any coffee at all.
Because caffeine makes your heart beat faster, people with heart problems used to be discouraged from drinking coffee altogether. A comparative study recently showed that even those who suffer from cardiac arrhythmia do not worsen their condition through moderate coffee consumption. However, caffeine can be dangerous for people with heart problems who, for genetic reasons, are less able to metabolize caffeine.
According to the WHO International Agency for Research on Cancer (IARC), there is reliable evidence of a protective effect against cancer of the liver and uterus. For other types of cancer, at least one risk from coffee cannot be identified. Overall, however, according to the IARC, the study situation is still unclear and contradictory.
Scientists from the US and Israel reported that drinking coffee reduces the risk of colon cancer. The drink contains ingredients like antioxidants that contribute to gut health, they explained.
As early as 2013, a meta-study published in the specialist journal “Geriatrics and Gerontology” analyzed 13 studies involving a total of 901,000 people in which the connection between coffee consumption and the risk of Parkinson’s was examined. It was found that people who drink an average of three cups of coffee a day have the lowest risk of developing Parkinson’s disease.
And ten years ago, a smaller Finnish meta-study from 2010 showed that a daily consumption of between three and five cups of coffee reduces the risk of developing Alzheimer’s in old age by 65 percent.
Scientists at the Krembil Research Institute in Toronto found in 2018 that coffee consumption can reduce the likelihood of developing a degenerative brain disease. Special compounds that form in the coffee bean during roasting are responsible for the protection. Since a long roasting time in particular creates the so-called phenylindanes, dark roasted, strong coffee varieties have the greatest positive effect on the brain.
Someone who drinks a lot of coffee every day will eventually be able to tolerate more of it than someone who only drinks a cup once a week. His heart won’t beat much faster after a triple espresso, and coffee won’t keep him from falling asleep. This is the case with the Munich food chemist Sara Marquart, who did her doctorate on coffee roasting. In an interview with the “Süddeutsche Zeitung” she admitted to consuming ten cups a day. However, the coffee has hardly any physiological effect on her because of the habituation effect.
“Coffee is a psychoactive substance, but it is not addictive. We’re more addicted to the ritual,” says the coffee expert. “We” are the heavy coffee drinkers who, for the 31-year-old, start with at least four cups a day.
If the “heavy drinkers” are suddenly refused coffee, withdrawal symptoms can develop, especially headaches. Sara Marquart explains it like this: “Adenosine receptors in the brain absorb caffeine when you drink coffee. When the caffeine is gone, adenosine comes into play again and this causes headaches.”
Not every adult tolerates coffee or its ingredients. Anyone who gets stomach pains, diarrhea or tachycardia from it will quickly voluntarily do without it.
However, coffee fans should also avoid it if they are pregnant. For the sake of the child, it should not be more than one cup. Because the caffeine reaches the fetus via the placenta, which can hardly break down this substance. Caffeine stunts growth and leads to low birth weight.
For breastfeeding mothers, two cups are okay again. In a report published in 2015, the European Food Safety Authority (EFSA) came to the conclusion that up to 200 milligrams of caffeine per day while breastfeeding is harmless. An infant and his liver, which is still not very resilient, could cope with this amount contained in two cups of coffee, each 150 milliliters.
Coffee in moderation can therefore be beneficial for the body. Not doing so can have health consequences. So it may be healthier to drink coffee than to abstain from it. Those who get jittery from regular coffee can still get their dose of antioxidants from decaffeinated coffee. If you don’t like the taste of the drink at all, you can switch to black or green tea. Both hot drinks taste less intense and also contain stimulating substances.
