Drinking a cup of coffee in the morning not only wakes you up for the day, it also helps the billions of friendly microbes living in your digestive system proliferate. Because according to a growing body of research, there’s evidence that your espresso can positively impact your microbiome (gut bacteria), leading to better overall health and even a longer life.
“The microbiome consists of legions of species of ‘good bacteria’ that work collectively and individually to improve our health,” says Nicola Shubrook, a registered nutritionist and functional medicine practitioner.
“These microbes increasingly appear to benefit our metabolic health, weight management, and mental health,” he continues. “Coffee contains several compounds that act as prebiotics, meaning that probiotics nourish beneficial bacteria by providing them with nutrients necessary for growth and function.”
Coffee’s effect on our intestinal flora appears to be twofold. First, caffeine itself acts as a stimulant, increasing the number of beneficial bacteria in the gut. “The more diversity in your digestive system, the better,” says Shubrook.
A 2023 study published in the journal nutrients investigated the relationship between caffeine, coffee consumption and the colon microbiome. The results showed that the microbiome richness and the number of beneficial substances increased in regular coffee drinkers. Alistipes And fecalibacteria types (thought to have preventive effects against liver fibrosis and cardiovascular diseases) and lower levels of harmful substances ErysipelatoclostridiumThis causes intestinal problems. This follows an earlier study in which coffee consumption was found to be associated with an increase in bifidobacteria, microbes thought to aid in the digestion of fiber and prevent infections.
Coffee also contains plant compounds called polyphenols, a category of compounds found naturally in plant foods such as fruits, vegetables, herbs, spices, tea, dark chocolate and wine. “Polyphenols act as an anti-inflammatory antioxidant,” Shubrook notes. “They may help reduce the risk of cancer by neutralizing harmful free radicals, which are chemicals that damage cells.”
The specific polyphenol in coffee is known as chlorogenic acid. According to a study published in 2020 Experimental and Clinical SciencesIt was observed that patients who consumed coffee rich in chlorogenic acid reduced the risk of Type 2 diabetes and non-alcoholic fatty liver disease and also lost weight. Scientists concluded that this was probably related to an increase in gut bifidobacteria (one of the “good” ones).
Established studies have also shown that caffeine is good for your gut, stimulating the colon and leading to regular bowel movements. A 1990 study showed that coffee drinkers tended to need the toilet within 30 minutes after drinking a cup.
In many ways, the gut seems to love a cup of Joe. So is there a best way to prepare and serve your coffee?
Black or milky?
Experts agree that black coffee is better for you than a cappuccino, latte or flat white. “Milk has been shown to inhibit the absorption of polyphenols,” says microbiologist Julia Kopczyáska from the Polish Institute of Biochemistry and Biophysics in Warsaw. “Adding tons of cream or sugar turns your coffee into something sweet. Sugars will do more harm to your blood sugar levels than coffee will do.
Which mix should I choose?
There are two main types of coffee beans: Arabica and Robusta. “Each of them has different qualities at certain roasting stages,” says Kopczyáska. “Although lighter roasts generally have higher caffeine content, they retain more antioxidants than darker roasts. Lightly roasted Robusta beans contain more antioxidants than yellow-roasted Arabica coffee.”
Most chain coffee shops in the UK use medium roasted Arabica beans, but Costa sells a blend of Arabica and Robusta. Black Sheep Coffee also sells Robusta.
“My preference is Exhale Coffee, a dark Arabica grown with the highest levels of antioxidants,” says Shubrook. “An excellent black coffee, not terrible at all.”
The length of time the beans are stored will also affect polyphenol levels, with a decrease seen in coffee beans stored for 12 months or longer.
How about instant coffee?
Although research shows that instant coffee may contain more polyphenols and minerals than ground coffee, it also contains 100 percent more of the chemical called acrylamide; Coffee substitutes can even contain 300 percent more. “Acrylamide is formed in coffee during the roasting process, and if people are exposed to higher amounts of it, the risk of nerve damage and cancer may increase,” says Kopczyäska.
However, there is no cause for alarm. “Consumption of coffee, both instant and ground, is not linked to the development of cancer,” Kopczyáska continues. “However
The European Food Safety Authority (EFSA) recommends reducing the amount of acrylamide in our diet. For this reason, we also recommend classic ground coffee instead of instant and substitute coffee.”
How many glasses should I drink a day?
A recent study of centenarians living in Europe’s “long-lived” Blue Zones of Sardinia and Ikaria in Greece found that almost all of them drank two to three cups of black coffee a day. “Assuming a cup of coffee is 8 oz per 8 ounces, two to three cups is the sweet spot and five is the upper limit,” says Kopczyäska.
Before grinding your beans or stamping your loyalty card, it’s worth keeping in mind the caffeine content of your drink. “Although coffee is beneficial, not everyone can metabolize it as efficiently,” Shubrook notes. Kopczyäska agrees. “The maximum recommended amount of caffeine is 400 mg per day. “Anything over 600 mg has been associated with insomnia and high blood pressure.”
According to Kopczyska, a cup of home-brewed coffee contains between 70 mg and 140 mg of caffeine, depending on the bean and brewing method. Meanwhile, the average high street coffee contains 180 mg of caffeine. Pret espressos and cappuccinos contain this amount. Others may be higher: A medium Costa cappuccino contains 325 mg; This meets almost all of your recommended daily needs in one cup.
You may be surprised to hear that most espressos are lower in caffeine than other types of coffee: 30ml/1oz Caffe Nero espresso has 45mg of caffeine, while Starbucks has only 33mg. Greggs espresso works at 75 mg. (But a cup of espresso is also a much smaller amount of liquid than a latte or cappuccino.)
How should I prepare my coffee?
How you trim your beans preserves different compounds that are beneficial to you and those that are less beneficial. Brewed coffee contains chemicals cafestol and kahweol, known as diterpenes. “Cafestol and kahweol are known for their anti-inflammatory, anti-diabetic, anti-cancer and polyphenol protective properties,” says Kopczyáska. “These are 30 times greater in unfiltered coffee.”
On the other hand, he says, unfiltered coffee contains fats that have been proven to raise cholesterol levels. “Filtered coffee not only contains less coffee oil but also less caffeine compared to unfiltered coffee brewing methods.”
If you can overcome the difficulties of using Aeropress, a 2023 study published in the journal foods revealed that this method was the best method to preserve polyphenols. “In our study, the lowest total polyphenol content was found in French press coffee (133.90 g gallic acid/liter) and the highest amount was observed in Aeropress coffee (191.29 g gallic acid/liter),” the authors wrote. “The highest antioxidant potential and polyphenol content was observed in the brew made in Aeropress.”
Can I make my coffee healthier?
Adding natural spices instead of sugar or syrup can provide extra health benefits. “Cardamon is an anti-inflammatory and regulates blood sugar levels,” advises Kopczyáska. “Ginger, a natural pain reliever, improves digestive health and lowers cholesterol. “If you use milk, turmeric added to the latte is known for its beneficial effects on metabolism and the immune system.”