Dec 2014 20

How much caffeine is too much?

By: Dave Wheeler

How do you kick-start your day?

For me, it's a double espresso. I can find good reasons to drink my coffee - research from John Hopkins University in Baltimore has shown that coffee can:

  • improve your cognitive skills (the quality and speed of your thinking processes)
  • improve your long term memory (your recall ability)

and as I get older, I need both of those!

But not surprisingly, the research kill-joys are only talking about a moderate amount of coffee giving us these benefits.


Pic by nokhoog_buchachon @


What counts as a "moderate" amount of caffeine?

The perceived wisdom seems to be that 3-4 cups of coffee a day is a moderate amount that will provide us with the good stuff that caffeine brings, but won't do much damage (for that read on).

But there's a problem there - the researchers (in Baltimore again) measured the amount of caffeine in a 480ml Breakfast Blend coffee from a local Starbucks. They did this for 6 consecutive days - ordering and then analysing the same drink bought each day from the same Starbucks store.

What they found was that the amount of caffeine in this "same" cup of coffee varied from 260mg up to 564mg.

Research in Glasgow confirmed these findings: 20 single espresso's were bought from different stores on the same day. They were found to contain between 56-196mg of caffeine, which is quite a variation.

Just to put that in a little perspective - 1 can of the energy drink "Monster" contains 240mg of caffeine.

So in answer to the question, "What's a moderate amount of coffee a day," thay's hard to say.

Researchers tend to use 75mg of caffeine (an average amount in a single esspresso) as definitive for a cup of coffee, so 3 or 4 single espresso's would be moderate. But as we've seen, in the real world, the amount of caffeine isn't often "average".


So what are the down-sides of too much caffeine?

Here's the list of nasties associated with drinking too much caffeine:

  • jitters
  • insomnia
  • anxiety
  • muscle tremors
  • headaches

There are suggestions based on kids OD'ing on energy drinks that too much caffeeine can have effects on your blood pressure and heart rate, but you'd be having to drink hundreds of cups of coffee a day to have anything more than a few seconds of a racing pulse.

The trouble is that caffeine is a drug. Like all drugs it's addictive. In the case of caffeine it's physically addictive - your body develops the need/craving for it.

If you think you drink too much coffee, it might be better to think about reducing your intake very gradually rather than going cold turkey.

Caffeine withdrawl can lead to:

  • headaches
  • irritability
  • depression

amongst other things. 

So better to wean yourself down to a "moderate" level very gently over a few months.

Now I'm not a nutritionist, so I'm not the person to help you if you need one - but I do know a couple of really good ones. If you need advice, leave me a message and I'll pass on their details to you.