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What does science think about coffee?

Written by: Svenja Schindler



Time to read 3 min

We wondered how much coffee is actually healthy and why we wake up from our blues after a delicious cup of coffee? We clarify conflicting information and explain current scientific studies on the effects of coffee.

Overview of key coffee facts

  • Coffee has many proven positive effects on the healthy adult body
  • Consumption of up to 400 mg of caffeine per day, or 2 to 5 cups of coffee per day, is not a problem.
  • Coffee is an important source of secondary plant substances
  • Caffeine cannot compensate for sleep deficit

What does science think about coffee?

If we type on the Internet the beginning of the sentence “Coffee makes .", we obtain additional search propositions such as "tired", "sick" or "beautiful". We find this rather confusing. But this information on the Internet also shows that there is a lot of misinformation and conflicting information about coffee.

For many years, coffee has been the subject of warnings and many myths about its harmful effects on health have been told. Recent studies, however, say the opposite and have profoundly improved the image of coffee. They even attest that regular consumption, but not excessive of course, of coffee has beneficial effects on health.

Recent studies have shown that coffee has similar health benefits to other fruits and vegetables. Plant foods contain secondary plant substances that are beneficial to health. Coffee is a plant product and has secondary plant substances comparable to tea, vegetables or fruits, so it is no less healthy. Coffee stands out in one respect: among people who drink it regularly, coffee is the main dietary source of secondary plant substances such as phenolic acids and polyphenols, even compared to green tea in Japan1.

A 2015 study linked high coffee consumption to a 20% reduction in skin cancer risk. Concretely, this reduced risk was observed in participants who drank 4 cups of coffee or more per day. The protective effect seemed to increase with higher consumption, from 1 cup or less to 4 cups of coffee or more2.

How much coffee is beneficial for your health?

For a healthy adult, consumption of up to 400 mg of caffeine spread over the day, that is to say approximately 4 cups of coffee, presents no risk3. This corresponds to 4 cups of coffee, 5 cups of espresso or 8 cups of black tea. Studies have shown that drinking 1 to 5 cups of coffee per day is associated with a lower mortality rate among non-smokers4.

Now in detail, the important component of caffeine!

Large studies demonstrate the positive effects of coffee on the human body. To better understand these studies, let's take a look at the body's absorption of coffee.

In the morning when we wake up, before an important meeting or after lunch, coffee helps us feel more awake and more focused. It is especially caffeine that plays an important role in this regard. Caffeine is a natural chemical compound found in particular in coffee and cocoa beans or tea leaves. If caffeine-containing drinks or foods are taken orally, it is quickly and completely absorbed by the human body. The effects of caffeine are usually felt 15 to 30 minutes after ingestion and can last for several hours.

Caffeine has been the subject of numerous studies and has many effects on the human body. Studies have shown positive effects on attention and speed of thinking processes5. Caffeine causes an increase in heart activity, metabolism and breathing. Additionally, blood pressure and body temperature increase slightly. Blood vessels dilate and blood supply to all organs increases. In case of fatigue, caffeine has a short-term stimulating and positive effect on wakefulness and performance. However, caffeine cannot compensate for a sleep deficit6.

Our conclusion.

The effects of coffee and caffeine are multiple and, according to many speculations, they are not harmful to health. According to the precautionary principle, current science recommends a maximum consumption of approximately 400 mg of caffeine per day or considers 2 to 5 cups of coffee per day to be no problem6.