How Genetics Affect Caffeine Tolerance

How Genetics Affect Caffeine Tolerance

How Genetics Can Affect People's Metabolisms with Caffeine


Caffeine is the world's most widely used and most addictive drug. It is found in chocolate, tea, and most commonly coffee. People drink coffee to stimulate their brain and stay awake longer or focus better, but it has been discovered that while sometimes it only takes one cup of coffee to get the desired effect for people, some others can drink three or four cups and feel no different. Why does this happen? It has been proven that genetics play an important role in people's metabolic abilities when it comes to caffeine.
Just as people have can have genes to determine their eye colour or their height, they can also have a gene to determine their resistance to caffeine. The particular genes are called CYP1A2 which metabolizes caffeine, and AHR which regulates CYP1A2 (Faber, K. 2013).
As with any gene, one copy is passed down to its offspring from each parent. The CYP1A2 gene has two different variations that parents can pass down through the generations; the first variation is CYP1A2*1A which allows people to metabolize caffeine faster, and CYP1A2*1F which allows people to metabolize caffeine slower (Faber, K. 2013). The copy with the 1F variation is dominant, making the 1A variation recessive. Not only are the variants of the CYP1A2 genes able to determine how quickly caffeine gets metabolized in the body, but are able to determine whether or not a person will have a caffeine dependency. People who have a higher rate of metabolizing caffeine will often need to consume more to keep the desired effects, whereas other people do not (Schenkman, L. 2011). On average, people with the high consumption variation of the gene will consume 40mg more caffeine per day than someone with the lower consumption variation.
What are the advantages of having one of the genes though? Researchers have proven that people who have the gene that metabolizes caffeine more slowly are at a higher risk of a non fatal heart...

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