Coffee is the most consumed drink in the world (after water), consumed by the entire planet two billion cups per day. But how hearty is all that caffeine? Surely nothing that addictive can be good for us?
It turns out it can—and it doesn’t seem to cause any significant harm. That’s according to a significant body of research on caffeine’s health effects over decades. Here are some of the key recent findings.
Good
You might think that, given what a few espressos can do to your heart rate, the effects of caffeine on that organ might be unpleasant. But many studies have shown benefits for the heart.
A study by scientists at the University of Bologna, published last year, found that Italians who drank one to three cups of coffee a day had lower systolic blood pressure and heart rate than those who didn’t drink coffee. Caffeine drinkers also had lower peripheral and central aortic pressure.
Another observational study found that people who reported drinking 1 or more cups of coffee per day had a lower risk of long-term heart failure (5-12% per cup of coffee per day) than their decaffeinated counterparts. Interestingly, the risk of heart failure did not change between 0 and 1 cup per day, but was about 30% lower in people who drank at least 2 cups per day.
Other reviews and meta-analysis also concluded that regular consumption of 3–5 cups of coffee per day was associated with a 15% reduced risk of cardiovascular disease, while higher consumption was not associated with an increased risk.
Even those who drink up to 25 cups a day (yes, you read that right) don’t seem to be at risk of stern heart problems. A 2019 study by the British Heart Foundation found that participants were not at greater risk of stiffening their arteries if they drank two dozen cups of coffee a day. The study also found that drinking a cup of coffee can stimulate the body’s brown fat, which generates body heat by burning calories.
Other obesity studies have shown that a cup of coffee can lend a hand maintain a hearty waistline.
People with genes that snail-paced down coffee metabolism were linked to lower body weight, body fat, and a lower risk of developing type 2 diabetes in a 2023 study. Researchers concluded that high blood levels of caffeine could reduce body fat.
A daily cup can also benefit the brain. In a recent preliminary in vitro In laboratory tests, compounds found in coffee have been found to inhibit the aggregation of tau protein, a process thought to be involved in the onset of Alzheimer’s disease.
Another study from last year found a positive association between coffee (and tea) consumption and the thickness of the macular nerve fiber layer of the retina – a lean layer of nerve cells that transmit visual information from the eye to the brain.
In the liver, caffeine also appears to lend a hand keep some liver diseases at bay. A 2015 meta-analysis of 16 studies found that coffee consumption could significantly reduce the risk of liver fibrosis and cirrhosis. Why? Scientists hypothesized that this energizing compound could reduce the expression of α-smooth muscle actin and procollagen, promoting liver healing.
Regardless of these potential health benefits, a cup of joe can make you feel a little more cheerful in the morning. One social study found that people gave more positive ratings for their group’s performance on a task—and their own contributions—if they had a cup of coffee beforehand.
Less good
However, the mood-boosting properties of caffeine may be just the thing to lend a hand. caffeine withdrawalwhich can cause headaches and irritability. However, if you overcompensate for this withdrawal, you may experience the negative effects of excessive caffeine consumption, such as anxiety and headaches.
These effects are more significant for some people. For example, people with panic disorder are more likely to have panic attacks if they drink five or more cups of coffee a day, according to one systematic review, and those who already live with insomnia are it’s probably going to be a long night if they drink before bed.
In scarce cases, high caffeine intake can lead to caffeine overdose. In one case studyA university student was taken to a hospital emergency room with nausea, heart palpitations, and vomiting after taking a caffeine energy supplement containing 6,000 milligrams (mg) of caffeine – about 60 times more than the typical concentration found in a cup of brewed coffee.
However, in smaller, regular doses, caffeine does not appear to be associated with any long-term, cumulative health problems, unlike many other drugs (alcohol, tobacco, etc.).
However, the safety certificate does not fully cover unborn babies. High levels of caffeine during pregnancy have been linked to miscarriages and low birth weight, which is why many national health agencies recommend against caffeine in pregnancy limit 200 mg per day2020 Review published in British Medical Journal even went so far as to say that “there is no safe and sound level of caffeine consumption for pregnant women and expectant mothers.”
Application
Caffeine is undoubtedly one of the safest recreational drugs. Although it has its drawbacks when consumed in excess, anyone who is not pregnant should be able to enjoy the refreshing taste of coffee without major health concerns.
