CAFFEINE...it's in my genes

May 5, 2017
3 min read

If you’re anything like me you should never be released from the house before your first coffee of the day! A recipe for disaster and a danger on the roads….That’s me! We all at the very least know someone, if you’re not one yourself, who just simply doesn’t function at their best until they have consumed that all important elixir... CAFFEINE.

I don’t know about you, but if I could have my coffee administered by IV infusion, I would.

Equally though, we all know someone who unthinkably doesn’t drink coffee. So many people say that coffee turns them jittery, prevents them from sleeping, or gives them a feeling of anxiety. So why is it that some people react so strongly to caffeine, where some of us can drink it as our nightcap and struggle to stay awake?

Caffeine is the key ingredient in coffee, the one ingredient that gives us that ‘BUZZ’, that feeling of euphoria. It is societies most commonly ingested stimulant, which causes dependence! Caffeine acts to increase the body’s secretion of adrenalin. It is in this way it acts as a stimulant, raising our energy levels and increasing our levels of alertness, explaining peoples perceived need for their morning cuppa.

The health and medical community, as with so many topics, struggles to come to agreement on the topic of whether caffeine is Tonic or Toxin. Whether caffeine causes heart disease or high blood pressure is conflicting; whether it causes cancer, again, undecided. The opinions on these ideas are ever changing …. Like riding a seesaw, one day we’re told it’s going to be the death of us, the next it is good for us!

I believe these seesawing views are due to the constantly conflicting evidence. But why is it some people can drink countless cups of coffee with little impact whereas others react quite strongly to it’s consumption?

The answer could be in our genes! That’s right, we could actually be genetically coded to our suitability for consuming caffeine. This little marvel is called CYP1A2. Simplistically, CYP’s are metabolic enzymes. Variations of these enzymes metabolise all sorts of substances from medications to alcohol, and you guessed it CAFFEINE! The specific enzyme CYP1A2, determines how quickly our bodies break down caffeine in the liver.

As with all things genetic, CYP1A2 is inherited differently in people. We all take half of our DNA from each of our biological parents. The dominance of certain aspects of our biology varies depending on which genes we’ve received from each parent and what their dominant genes are. That’s why you can have two siblings that look poles apart.

So when it comes to inheriting the ‘CAFFEINE GENE’ this too comes down to whether we inherit the fast or slow variant of the gene (a bit like some athletes having a dominance of fast or slow twitch muscle fibres, thereby determining the types of sports they would be more suited to).

So if you inherit two fast variants of the gene, your body will metabolise caffeine very quickly, meaning that you can drink more without feeling that same ‘buzz’ that some people get.

If you inherit one fast and one slow, your body will metabolise caffeine more slowly, giving it a more lasting effect on you.

If, and this would be unlucky, you inherited two slow variants of the gene, your poor body will struggle to metabolise caffeine and quite possibly limit you to one a day…. if that! It’s these poor souls that, tip them over the threshold and they’ll be up all night trying to rock themselves to sleep.

It would be reasonable to think that if some people are metabolising caffeine more quickly than others, and the substance is spending less time in their bodies, perhaps they actually run less of a risk of heart disease and high blood pressure, and this is why the studies on the effect of caffeine on the human body are so inconclusive! Maybe, just maybe, there’s something in this.

As with so many things, it really does come down to the individual and listening closely to our own bodies before accepting any literature as Gospel. Nobody knows your body the way you do, learn to be in tune with it, learn to listen!