Caffeine Sensitivity: Is that second coffee helpful or harmful?

• That extra dose of liquid productivity is actually quite healthy for some and yet it’s not so good for others.
• People who metabolize caffeine very quickly might not feel any effect at all, while those who metabolize it more slowly might feel anxious or jittery.
• It is important to note that caffeine sensitivity is not the same thing as caffeine tolerance.
• According to a study by the National Institutes of Health, slow metabolizers of caffeine have increased risk of heart attack when they consume coffee, while fast metabolizers actually gain protection against heart attack from the same amount.

There is nothing quite like that first cup of steaming hot coffee in the morning. Or the second cup for that matter. Or the third. But is all that caffeine really good for you? There is conflicting data. That’s because that extra dose of liquid productivity is actually quite healthy for some and yet it’s not so good for others.

The reason for this difference has to do with the speed at which different people metabolize caffeine – that that speed is influenced by genetic variants.

WHAT IS CAFFEINE SENSITIVITY?

How do you feel after consuming coffee, tea or energy drinks? People who metabolize caffeine very quickly might not feel any effect at all, while those who metabolize it more slowly might feel anxious or jittery. The difference between fast metabolizers and slow metabolizers lies in the CYP1A2 gene which triggers the enzyme responsible for breaking down caffeine. People who are sensitive to caffeine produce lower amounts of this enzyme. Those who inherit 2 copies of this gene variant (about 45% of the population) are fast metabolizers.

The AHR gene also effects how caffeine-sensitive a person will be because it works to turn the CYP1A2 gene on and off. Those who drink four or more cups of coffee per day are more likely to be carriers of this AHR gene variant[i]

It is important to note that caffeine sensitivity is not the same thing as caffeine tolerance. Caffeine tolerance happens when your body has less of a response to caffeine because of regular use. Caffeine tolerance does not mean that your body is metabolizing it any quicker. This is an important distinction because too much caffeine in caffeine-sensitive people has been linked to health problems.

HEALTH EFFECTS OF CAFFEINE

Earlier in the article we mentioned that an extra cup of joe in the morning might be healthy for some and unhealthy for others. According to a study by the National Institutes of Health, slow metabolizers of caffeine have increased risk of heart attack when they consume coffee, while fast metabolizers actually gain protection against heart attack from the same amount.[ii]

The reason for this is that fast metabolizers are not as vulnerable to the negative effects of caffeine as it breaks down more quickly, yet they are still getting all the healthy benefits of coffee including antioxidants and polyphenols.

BENEFITS OF TESTING

While CYP1A2 is the main genetic variant responsible for caffeine sensitivity, it is not the only one.[iii] Coffee drinkers who learn that they are sensitive to caffeine might consider cutting back, switching to decaf or another coffee alternative. This would be especially advisable for those who already have an existing heart condition.

At GeneBlueprint, we test for a wide range of genetic variants and can help you discover whether that second cup of coffee in the morning is really helpful or harmful.

[i] http://www.gbhealthwatch.com/Trait-Caffeine-Consumption.php

[ii] Coffee and Caffeine Genetics Consortium et al. “Genome-Wide Meta-Analysis Identifies Six Novel Loci Associated with Habitual Coffee Consumption.” Molecular psychiatry 20.5 (2015): 647–656. PMC. Web. 31 Aug. 2017.

[iii] https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4388784/