What Is Caffeine Sensitivity? A Deep Dive Guide

We think that more and more research will come to light about caffeine and its effects. Everyone is different and caffeine has many health benefits, but, at the same time, for some of the population, it’s clearly has a negative effect.

First of all, caffeine sensitivity is determined by the efficiency of the human body to process and metabolize caffeine. Most importantly, this shouldn’t be confused with caffeine tolerance, which describes how the body responds to caffeine over time. Sensitivity is more about your genetic makeup since this determines to what degree a given amount of caffeine will affect a person.

It all begins with the liver where caffeine is metabolized using the enzyme CYP1A2. The ability to produce this enzyme is regulated by the CYP1A2 gene. Amazingly, just a few slight changes in the DNA sequence of this gene determine how efficiently a person can metabolise caffeine and thus eliminate it from the body. And it varies a lot. Some people genetically produce very little of this enzyme while others produce a large amount.

What percentage of people are sensitive to caffeine?

The majority of humans are somewhere in the middle. Then, there are the 10% of the population who are rapid caffeine metabolizers and thus not very caffeine sensitive (the ones who drink a double espresso at midnight, then go to bed!).

Finally, it also depends on what type of adenosine receptors a person has in the brain. Again, genetics. Those lacking the correct adenosine receptors in their brain are unresponsive to the awakening effects of caffeine because the caffeine molecule cannot properly bind to the receptors.

The latest research from The Harvard School of Public Health has indeed found six more new genetic variants associated with the way people metabolize and form addiction to caffeine.

So, what does this mean? Based on the research so far, there are three levels of caffeine sensitivity:  

1. Hypersensitive to Caffeine 

These people react to very small amounts of caffeine. Even at amounts less than 100 mg, people who are hypersensitive to caffeine can experience overdose symptoms such as insomnia and an increased heartbeat since it can take as much as twice as long for caffeine to metabolized. In this case, decaf coffee is not even suitable for them. 

 2. Normal Sensitivity to Caffeine

People who show normal sensitivity to caffeine can usually have 200-400 mg of caffeine daily without any adverse reactions. This applies to the majority of mankind and, for these people, they have no trouble sleeping as long as the caffeine is consumed early enough in the day. Decaffeinated coffee is definitely suitable for this group.

 3. Hyposensitive to Caffeine

Then, there’s the ten percent of the human population who are hyposensitive to caffeine. This means that they process caffeine so efficiently that even taking large doses ( >500 mg) does not have much effect at all. Those hyposensitive can also consume caffeine shortly before bedtime and still get a good night’s sleep. They can definitely drink decaf coffee without a problem!  

So, what’s your caffeine sensitivity level?

From our descriptions, you should be able to identify your level of caffeine sensitivity.

For those hypersensitive to caffeine, we recommend that they cautiously consume caffeine and avoid highly caffeinated beverages like coffee and energy drinks. Black tea, green tea or decaf coffee is probably a wise choice for this group.

Those with normal sensitivity should be aware of how much caffeine they are consuming and keep this within the daily safe dose guidelines of between 300-400 mg. This equates to 2-3 cups of brewed coffee or 7-8 cups of black tea.

Again, decaf coffee is also allowed and helps balance the caffeine equation. Then there’s the hypersensitive people who should evaluate the necessity of caffeine.

If large amounts of caffeine do not create the desired effects such as wakefulness, alertness, and productivity, then we would question the benefits of consuming it apart from the taste. There is a danger of overdosing on caffeine by mistake as they don’t feel the effects. Decaf coffee is a safe option.

While the above guidelines and caffeine sensitivity levels may apply to many, there are some that could fall somewhere in the middle. What about doing a caffeine detox? We’ll come to that in another blog posting!