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The DNA Diet that Determines how much coffee is healthy for you!

“Your next coffee could be your last” was the front page of The Sunday Times newspaper when the news broke about the CYP1A2 gene that makes the general dietary guidelines for caffeine dangerous to 50% of the population. This is no joke and below is an outline of how genetic insights such as those from the DNA Diet ‘The DNA Way’ can help you understand how to prevent a catastrophic cardiovascular event.

How much caffeine is safe?

Many countries in the world, including the UK, state that the safe limit for caffeine consumption is 400mg per day. This may look like 2 coffee shop coffees (each usually made with 2 espressos) however nutrigenomic studies clearly show that 400mg would not be safe for 1 in 2 people, all dependent on which variant of the CYP1A2 gene they carry (1, 2)

Protip: caffeine is found in more foods than you would think: tea, coffee, fizzy drinks and even chocolate contain caffeine – so if you are a slow metaboliser you should be very mindful of this!

Caffeine content of food/drinks:

  • Espresso (1 shot) 85mg
  • Black tea (1 cup) 50mg
  • Green tea (1 cup) 45mg
  • Coke (1 can) 34 – 46mg
  • Energy drinks (1 can) 80 – 200mg
  • Decaf coffee/tea (1 cup) 0 – 15mg
  • Herbal tea (1 cup) 0mg

How does the DNA Diet determine my caffeine requirements?

The CYP1A2 gene produces an enzyme that has the main function of breaking down the caffeine in the body. If you carry the GA or AA genotype of this gene, you are considered a “slow metaboliser” of caffeine, and therefore the DNA diet ‘The DNA Way’ will suggest you decrease your intake to be safe. These slow metabolisers break down caffeine slowly and are at greater risk of high blood pressure and a heart attack if they consume more than 200mg of caffeine each day never mind 400mg! It’s scary to think that 50% of us may be at risk of a heart attack by following public health guidelines of 400mg per day.

You may decide to want to err on the side of caution and reduce your caffeine intake to 200mg per day. BUT according to the DNA diet ‘The DNA Way’, this is where it gets even more interesting… If you are a fast metaboliser of caffeine (GG genotype) you can enjoy 300-400mg of caffeine per day to actually help protect from high blood pressure and a heart attack in the future! How crazy is that! Scientists think that fast metabolisers excrete the caffeine so effectively that the beneficial compounds in coffee/tea such as polyphenols etc are able to make their way to the cardiovascular system and work wonders.

Why you can’t guess your safe caffeine requirements

Science becomes even more fascinating if you are someone who thinks that you know if you are a slow or fast metaboliser instinctively because of stimulation you feel after sipping on your delicious coffee. The stimulating effect of coffee is unfortunately down to a completely different gene that alters stimulating receptors in the brain. The DNA diet ‘The DNA Way’ uses this robust science from the likes of Harvard to precisely determine your dietary requirements.


(1)Cornelis et al. Coffee, CYP1A2 genotype, and risk of myocardial infarction. Journal of the American Medical Association. 2006;295:1135-41.

(2) Palatini P et al. CYP1A2 genotype modifies the association between coffee intake and the risk of hypertension. Journal of Hypertension. 2009;27:1594-1601.

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