Are you a slow or fast caffeine metabolizer


Cozy cafes are traditional places to meet friends, acquaintances, family or co-workers. After all, the most common invitation to a meeting is probably the obligatory question, "Shall we go for a coffee?". You meet at the café, order your usual Flat White and your friend declares she'll have anherbal tea, as she's already had her coffee today.

You wonder how she could have lasted until the afternoon with only one cup of coffee, while you've managed to drink three cups since this morning and can't imagine your day without this regular caffeine refill? Why is it that someone needs to basically replenish himself with one cup of coffee after another, while another just needs one cappuccino in the morning and has enough energy in the evening?


The answer is written in our genes. Ourunique genetic makeup determineshow sensitive we are to caffeine, i.e. our ability to process and metabolize caffeine. Caffeine sensitivity is a measure of the given amount of caffeine that affects us. Over the years, caffeine sensitivity can change as our gene expression changes with aging.

Thegene that determines our sensitivity to caffeine is called CYP1A2. It is able to produce the same named enzyme CYP1A2, which takes care of metabolizing caffeine in the liver. The efficiency of caffeine metabolism is due to slight changes in the DNA sequence of this gene. Depending on how the gene-driven production of the CYP1A2 enzyme occurs, we can generally assign ourselves to one of three categories or types of caffeine sensitivity.


People hypersensitive to caffeine react to even a small dose of caffeine. They may experiencesymptoms of "cavitation" or caffeinism at amounts as low as 100 mg. This means they may experience a rapid heart rate, nervousness or insomnia after less than one cup of coffee. Also, the decaffeination process takes longer.

In these people, caffeine metabolismcantake up to twice as long. People who are sensitive to caffeine are generally advised to be cautious with their coffee consumption or choose a drink with less caffeine such as black or green tea.


Mostpeople fall into this group . On average, they can consume 200 - 400 mg of caffeine per day, which is about 2 - 4 cups of coffee, without adverse effects. Coffee also does not interfere with their sleep if they consume it at a reasonable time to allow the caffeine to break down before bedtime.


This last group consists of about 10% of people who, because of their low sensitivity to caffeine, can consume higher doses of caffeine without problems. Their processing of caffeine is so efficient that they can indulge in more than 500 mg of caffeine, i.e. about 5or more cups of coffee, during the day and even haveno problem having coffee shortly before bedtime.

The downside for these people is their tendency to drink too much coffee. If even large doses of caffeine do not produce the expected effects such as dampening drowsiness and increasing productivity, we may question the benefits of consuming such large amounts of caffeine intake. Drinking large amounts of coffee daily could then have negative consequences for a person's health over time.


According to these characteristics, you can guess for yourself which group you belong to. Since the middle group of normal caffeine sensitivity is the most prevalent, it can include people whose ideal caffeine dose for the day is one cup of coffee, as well as those who metabolize 4 cups of coffee a day just as efficiently.

From this perspective,you'll probably lean more towards the high or low caffeine sensitivity group. In general, then, you might describe yourself as a slow or fast caffeine metabolizer. To drink coffee healthily, it is important to be aware of your body and how caffeine intake affects it, so that you can find your ideal amount - your personal daily dose of caffeine.


By gradually understanding and mapping the human genetic code, scientists are uncovering various facts about how humans function that are written into our very being. In addition to recognizing the CYP1A2 gene and uncovering its ability to metabolize caffeine, they have discovered theAHR gene, among others . It also plays a role in caffeine sensitivity. It regulates the switching on and off of the aforementioned CYP1A2 gene.

We must not forget the genetic link between caffeine sensitivity and the type of adenosine receptors that are inside the brain. It is caffeine, in addition to adenosine, that is picked up by these receptors. People who lack the correct adenosine receptors in their brains do not experience the stimulating effect of caffeine because the caffeine molecule has nowhere to actually bind.


In recent studies, we are learning about other genetic predispositions that affect caffeine processing in our bodies. While the CYP1A2 gene determines consumption at higher levels of caffeine, the PDSS2 gene is thought to determine caffeine sensitivity at lower levels of consumption.

In a study by scientists at Harvard University, we learn about 6 new genetic variants that affect the way caffeine is metabolized and addicted. 120,000 people participated in the research and the results revealed 2 genes related to how caffeine is metabolized, 2 more genes that affect the expression of feeling rewarded for consuming caffeine, and then 2 more genes with the ability to regulate fats and sugars to caffeine. 1)


Innate caffeine sensitivity, which can also change with age, relates to the processing of the caffeine molecule in the body. Theability to tolerate caffeine isalso related to consuming a certain amount of coffee. How a person responds to a dose of caffeine. If you have been avoiding coffee or have refrainedfrom drinking coffee for some timeyou will have zero tolerance to caffeine.

In the following days, if you keep drinking the same dose of coffee, you will feel its stimulating effects such as extreme alertness, increased motivation and energy and good mood, but they will already be experienced to a lesser extent. This tolerance is similar to, for example, drug tolerance, where thedose taken must be increased over time to achieve the same high effects.

With caffeine tolerance ,adenosine receptorsare again involved . Your body decid es tocompensate for the caffeine-blocked receptors with new ones so that the adenosine has somewhere to bind. With the newly developed receptors, there is then a need to block them with caffeine as well to prevent fatigue. And for this task, you need more coffee.


By continually increasing the amount of coffee you drink in a day to achieve the same positive and enticing effects, you can soon get to excessively high daily doses of coffee that may no longer be beneficial to your health. On the contrary.

Higher consumption is also associated with agreater change after the effects of coffee wear off, the so-called caffeine crash or caffeine decay. This condition can manifest itself not only in greater fatigue and a drop in activity or blood pressure, but also in psychological problems leading, for example, todepression and anxiety.

Increasing tolerance to caffeine is similar to drug addiction and is thus one of the reasons why coffeeisa drug you can become addicted to. Unlike a destructive drug addiction, drinking coffee is more of a habit. When chronic coffee drinking is discontinued, the body again "resets" to its original natural state.