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Specialist Advice — 6 minutes

Your DNA determines your reaction to caffeine

Catherine Drouin-Audet, Dt.P
Catherine Drouin-Audet, Dt.P
Assistant Director of Operations BiogeniQ

If you were told that your usual morning coffee or tea could be either good or bad for the health of your heart, wouldn’t you want to know what that means for you?

Inside these hot, comforting beverages hides a psychostimulant – caffeine – which could have either a positive or negative effect on your health, depending on your DNA.

The effects of caffeine on the body

Caffeine is the most widely consumed psychostimulant in the world. [1] It is found, of course, in coffee and tea, but also in colas, energy drinks and dark chocolate. It is so present in our lives that we sometimes forget to ask ourselves whether it is actually good for our health. Some argue that it is, while others have the opposite opinion. [2]

Given the mountain of information available today at our fingertips, how can we make sense of these competing claims? What makes it difficult is that this organic compound affects the human body differently from person to person.

Caffeine acts not only on the central nervous system, but also on the cardiovascular system. When consumed sporadically, it increases blood pressure and dilates the blood vessels. [3] In some people, these immediate effects result in a feeling of well-being, while in others they produce uncomfortable palpitations that last several hours.

The immediate effects of caffeine are well recognized and documented. However, there remain questions regarding the impact of frequent, long-term consumption of this substance on cardiovascular health. On this issue, opinions are far from unanimous. [2]

The effects of caffeine on the body can vary from one person to another, since each person reacts differently to this psychostimulant.

Your DNA influences your reaction to caffeine

While age, addiction, smoking and the taking of medications all affect a person’s reaction to caffeine, genetics are also an important piece of the puzzle. In fact, the rate of elimination can be up to forty times faster or slower from one individual to another depending on their genetic code. [4]

After being absorbed by the digestive system, caffeine circulates in the blood and passes through the liver. This organ contains the CYP1A2 enzyme, whose job is to lightly transform the caffeine molecule so that the kidneys can gradually eliminate it. [1] People who can eliminate caffeine quickly are categorized as rapid metabolizers. Others, due to a genetic variation that slows this process, eliminate caffeine more slowly and are known as slow or intermediate metabolizers.

It has been demonstrated that slow and intermediate metabolizers have an increased risk of hypertension and a myocardial infarction if their usual caffeine intake exceeds 200 mg per day. In contrast, rapid metabolizers see little to no increase in their blood pressure or risk of heart attack with a caffeine intake of 100 mg to 400 mg per day [1-5].

Therefore, a supposedly healthy diet can still put you at risk of developing chronic diseases if it does not meet your body’s unique needs.

Dependency and genetic predisposition

In 2011, American researchers and scientists studied the possible link between caffeine consumption and the perceived need. By analyzing the DNA of more than 40,000 people, they were able to identify two genetic sequences that are responsible for the desire to drink a coffee, tea or soft drink or eat chocolate. This suggests that each individual’s genetic profile determines whether or not he or she feels the need to consume these stimulants, and how often.

When all is said and done, we can see that, depending on the person consuming it, caffeine can have a positive or negative effect, whether we are talking about weight management or cardiovascular, metabolic, bone or immune health. I suspect that you will be looking at your next cup of coffee with a whole new perspective!

  1. CORNELIS, M. C. et al., “Coffee, CYP1A2 Genotype, and Risk of Myocardial Infarction,” Journal of the American Medical Association, 295, 1135-41 (2006)
  2. CORNELIS, M. C., “Gene-coffee interactions and health,” Current Nutrition Reports, 3(3), 178-195 (2014)
  3. YANG, A. et al., “Genetics of caffeine consumption and responses to caffeine,” Psychopharmacology, 211(3), 245-257 (2010)
  4. KALOW, W. and TANG, B. K., “Use of caffeine metabolite ratios to explore CYP1A2 and xanthine oxidase activities,” Clinical Pharmacology & Therapeutics, 50:508–519 (1991)
  5. PALATINI, P. et al., “CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension,” Journal of Hypertension, 27, 1594-601 (2009)
  6. KASHUBA, A. D. et al., “Quantitation of three-month intraindividual variability and influence of sex and menstrual cycle phase on CYP1A2, N-acetyltransferase-2, and xanthine oxidase activity determined with caffeine phenotyping,” Clinical Pharmacology & Therapeutics, 63:540–551 (1998)