• Kate

Are you a Slow or Fast Metaboliser of Caffeine? The answer is in your Genes!

A study was published in the Journal of the American Medical Association, which determined that in some individuals, caffeinated coffee intake decreased the risk of heart attacks. But in others the same dose of caffeinated coffee increased the risk of heart attacks and this was down to genes.

Individuals who had what we call a ‘slow’ version of the gene CYP1A2 (a gene that breaks down caffeine in the liver) have an increased risk of a heart attack when increasing consumption of caffeinated coffee. However, those who have the ‘fast’ version of CYP1A2, have a decreased risk of heart attacks with moderate intakes of caffeinated coffee around 1-3 cups per day.

The reason why those with the ‘fast’ version of the gene might benefit is because they can break down caffeine very rapidly, getting rid of the caffeine while preserving the beneficial antioxidants in the coffee. It’s these antioxidants, not the caffeine, which may provide protection for the heart.

All in all, caffeine itself probably isn’t good for anyone in regards to heart disease. But, if you can eliminate it swiftly because you’re a ‘fast’ metaboliser of caffeine, then you may benefit from the other compounds in coffee or tea, which are great sources of antioxidants.

Some people who haven’t been DNA tested and don’t know if they are actually a fast or slow metaboliser of caffeine think they are definitely ‘slow’ metabolisers of caffeine, because if they have a coffee in the afternoon, it will keep them awake all night. But, this just means that caffeine connects more efficiently to a specific receptor in the nervous system - this is how caffeine acts as a stimulant. It does not tell you about how quickly caffeine is broken down by the liver, which is the main organ that’s responsible for metabolising caffeine.

The only way to know if you’re a’ fast’ or ‘slow’ caffeine metaboliser is by having a DNA test.

Also, an important fact to take note of is that by being a ‘fast’ metaboliser for caffeine doesn’t necessarily make you a ‘fast’ metaboliser of any other dietary factor. The enzymes coded by each gene are quite specific to the compounds they metabolise – you can only really know how you metabolise different nutrients by having a DNA test. At the What IF Plan (www.thewhatifplan.co.uk) you can take your diet and fitness DNA test and find this information out. Knowing this one nugget of information has changed so many of my client's lives - for the better!