Everything about the most popular magic potion

Which health-promoting ingredients does coffee contain?

The well-known component of coffee is, of course, caffeine. “Coffee is often equated with caffeine, but coffee beans actually contain over 100 biologically active compounds. These substances can help reduce oxidative stress and inflammation, improve insulin sensitivity, boost metabolism, inhibit fat absorption in the gut, and block receptors known to be involved in abnormal heart rhythms,” says Dr Peter M. Kistler, professor and head of arrhythmia research at the Alfred Hospital and Baker Heart Institute in Melbourne, Australia. 

In fact, scientific studies using decaffeinated coffee often show the same effects as caffeinated coffee. So it is not only about caffeine. In addition to hundreds of other substances, coffee provides us with potassium, magnesium, calcium, antioxidant chlorogenic acid, carbohydrates, proteins, oils and 100 aroma compounds that create coffee's distinctive bitterness – including, naturally, caffeine.  

Why are espresso and filter coffee considered particularly healthy?

The health effects of coffee also depend on how it is prepared. Espresso and filter coffee are regarded as healthier than some other brewing methods.

When preparing espresso, high pressure is used to force hot water through the finely ground coffee. As a result, espresso contains less acidity and is better tolerated by people with a sensitive stomach. 

When preparing filter coffee, the substances cafestol and kahweol are retained in the filter; in high amounts these can raise the cholesterol level.

How does coffee affect digestion?

After drinking a cup of coffee, the body's hormone gastrin is released in increased amounts. This leads to a higher production of hydrochloric acid, which sensitive people may not tolerate well. 

The food bolus is broken down faster and passed into the intestine. There, coffee stimulates the muscle contractions in the colon wall and thus activates peristalsis. 

Chlorogenic acid, which is abundant in coffee, also has a digestion-promoting effect: it stimulates bile flow and helps digest fats. In addition, coffee causes our bodies to produce more the digestive hormone cholecystokinin. This hormone is responsible for releasing certain digestive enzymes and contributes to bile production by stimulating the contraction of the gallbladder. 

What effects does caffeine have on the body?

Moreover, the bitter compound caffeine is absorbed through the stomach and small intestine within 30 minutes after drinking coffee and is distributed throughout the body. Essentially, caffeine behaves like an everyday drug, as its chemical structures resemble those of amphetamines such as cocaine or methamphetamine. People react very differently to this “drug”. Their reaction partly depends on whether the liver metabolises caffeine slowly or quickly. 

Another factor is the sensitivity of the central nervous system to caffeine's stimulating properties. If someone has a slow liver metabolism and a strong binding in the central nervous system, even small amounts of caffeine will have a stimulating effect. People with a good balance between liver inactivation of caffeine and its binding in the central nervous system can drink up to five cups of coffee a day without suffering from sleep problems. With low sensitivity to caffeine, larger amounts can be consumed and one can even drink a cup of coffee before bedtime, as caffeine is then metabolised quickly by the body.

What positive and negative long-term effects does regular coffee consumption have?

Studies suggest that regular coffee consumption can boost metabolism during exercise, reduce the risk of type 2 diabetes and colorectal cancer, and have a slight positive effect on life expectancy. Regular consumption of three to five cups of filter coffee a day can lower the risk of coronary heart disease and stroke – and this applies even to people with high blood pressure. In addition, unsweetened black coffee can protect against tooth decay: the chlorogenic acid, nicotinic acid and trigonelline it contains kill decay-causing bacteria. These positive health effects apply to coffee both with and without caffeine.

However, too much coffee is not healthy and can cause insomnia, increased blood pressure, malaise, stomach problems and nausea and reduce fertility. High amounts of caffeine increase the release of the stress hormone adrenaline, making it harder to relax. 

Furthermore, caffeine is structurally similar to the neurotransmitter adenosine. Adenosine tells our body when we need rest and sleep. Caffeine blocks its receptors, so you may not feel sleepy but still feel constantly tired. The brain can also become accustomed to caffeine. Pregnant women should avoid coffee completely: caffeine crosses the placenta into the baby's blood and can harm it.

Rethinking coffee – how to make the most of it in everyday life

• Do not exceed the recommended daily dose, which is a maximum of three to four cups of coffee (about 400 mg of caffeine). After a cup of coffee, caffeine can generally act for up to four hours, although this varies from person to person.
• Do not drink coffee immediately after getting up. At that time the stress hormone cortisol is released and coffee can amplify its effect. One to two hours after getting up, cortisol levels usually drop and you can enjoy your cup of coffee calmly.
• Be aware that milk fat delays the absorption of caffeine. If you drink your coffee with milk, the duration of the caffeine effect is therefore extended.
• Pour the ground coffee with water heated between 90 and 95 degrees. With hotter or boiling water your coffee will taste bitter, be harder on the stomach and its aroma will evaporate quickly.
• Pay attention to water quality: it affects the taste of coffee. Water that is too soft makes coffee tasteless.
• For most people, it is advisable not to drink coffee after 2 pm or to switch to decaffeinated coffee, because our body needs time to fully clear caffeine from the bloodstream.
• For mild migraine attacks, coffee with the juice of half a lemon can help: coffee constricts blood vessels that are dilated by migraine, and the vitamin C from the lemon increases the formation of a messenger that can reduce headache.
• If you didn't finish the brewed coffee, you can freeze it in ice cube trays. Later you can use these cubes for iced coffee or dissolve them in hot milk. Or boil the cooled coffee with the same amount of sugar on low heat and refine drinks and dishes with this syrup, which keeps refrigerated for about six months.
• For a beauty scrub, mix used coffee grounds with a little olive oil to remove dead skin cells and promote circulation and cell renewal.
• Warm used coffee grounds are great as an anti-cellulite treatment. Wrap them tightly in a towel or cling film around the thighs and leave for about 15 minutes.
• A cup of strong, cooled coffee can be used as a hair rinse for dull, brittle hair. Pour the coffee over freshly washed hair, leave briefly and then rinse thoroughly.
• Used coffee grounds can help against hair loss. Take about half a handful of grounds, massage them into the wet hair and scalp, leave for about half an hour and then rinse out.
• Coffee helps eliminate unpleasant odours in the fridge or a room. Simply place a small bowl of coffee grounds. You can also rub your hands and the chopping board with grounds after cutting onions.
• Because of the nitrogen, potassium and phosphorus it contains, coffee can be used as a fertiliser substitute for plants that need acidic soil. Dilute coffee with water in a 1:1 ratio and water the plant with it every four weeks.
• Used coffee grounds serve as a chemical-free cleaner for stubborn dirt in pans or on the grill grate. However, do not use grounds to clean ceramic glass hobs.
• Used coffee grounds can help repel wasps. Let the grounds dry, fill them into a fireproof dish, place it on the balcony or terrace and light the grounds.

With these tips you can enjoy your coffee with a clear conscience, so that this beverage, rich in hundreds of plant compounds, becomes part of your healthy lifestyle!