Too much coffee?

Posted by Andrew Wadge on August 15th 2007 in Science, safety and health

Tuesday’s (14 August 2007) papers reported that a 17-year-old girl landed in hospital after drinking seven double espressos. Espresso is indeed strong stuff, with relatively large amounts of caffeine in each cup, but the effect it had on her was almost certainly due to the number of cups she drank. And some people are more susceptible to the effects of caffeine than others.

Posters in antenatal clinics remind us that one of the major concerns about caffeine is to do with possible effects of drinking too much coffee during pregnancy. This is because pregnancy is when the risk of effects is greatest.

The FSA is currently funding a study to look at caffeine consumption in pregnancy to find out whether women should moderate their caffeine intake while they’re expecting. The work was commissioned in 2001 following a review by the Committee on Toxicity (COT).

The COT looked at the possible effects of caffeine on the development of unborn babies. High caffeine intake was associated with an increased risk of low birth weight and miscarriage – high caffeine intake being 300mg of caffeine per day, equivalent to four mugs of instant coffee, three single expressos or six cups of tea. The COT highlighted the need for further research to clarify whether moderate caffeine intakes could affect unborn babies.

The current study aims to be as comprehensive as possible, using a large number of women and including all dietary sources of caffeine, such as tea, cola and chocolate. Once complete, the study will be reviewed by the COT and it is expected to report within the next year. 

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Coffee and interactions with other beverages

Posted by Anonymous (not verified) on 17/09/2007 - 14:42

It's not just the caffeine, there is something else in coffee. As the other poster noted when consuming both tea and coffee the coffee seems to amplify the caffeine in tea. This is my experience also. Specifically, if I consume a couple of cups of tea (strong, black) AND then one cup of decaf, then I am jumpy, having all the other effects of having "too much caffeine." Tea alone, no effects felt. More research needed. It's not the caffeine!

caffeine

Posted by Alex (not verified) on 06/09/2007 - 11:39

you mention tea, cola & chocolate... what I find alarming is the rate at which high caffeine drinks are consumed (like Red Bull with 80mg caffeine per can), especially by young children on their way to school. might this have something to do with the rise in diagnosis of ADHD?
this is just an observation of mine, nothing scientific

talking about self promotion

Posted by Anonymous (not verified) on 26/08/2007 - 15:24

I certainly believe that your post is again more to do with publicising the work of your colleagues at the Agency rather than really talk about the toxicity of ingesting larger amounts of caffeine during a short period of time.
Talking about the particular case of that 17 year old girl , 7 expressos seems a large amount of coffee to have in one go and I will wonder myself... why she did it? was see feeling sick or down due to a long night out? did she have any other medical problems that the newspaper forgot to mention?.. Certainly the new itself does not catch the eye of many people... unless quite conveniently, you will try to pinpoint a possible blame even if we are not prepared first to consider the facts and the real evidence of that particular case.
A very typical example on how to create an issue out of very little , with a little bit of luck... we shall be soon baning caffeine as well

Too much coffee

Posted by Andrew Wadge on 24/08/2007 - 14:11

Thanks for replying Bibi. You highlight an important principle of toxicology. It's the dose that counts. Another factor is the variability between individuals in the way that we metabolise and respond to compounds such as caffeine. Our susceptibility to the effects of high levels of caffeine will vary from individual to individual, but it sounds like you have already worked out the intakes that you are comfortable with.

Too much coffee in close proximaty

Posted by bibi (not verified) on 23/08/2007 - 17:45

I also think it is relevent in the caffeine debate to note how much is drunk in too short a period of time. I drink one cup of coffee and three cups of tea a day, both with milk, no sugar, I'm fine with these and believe it to be a healthy amount. But if I drink my coffee within an hour of my last cuppa or if I even drink my one cup of coffee too fast rather than sipping it, I find my heart is racing very fast, I feel mildly sick and a bit odd, this lasts for about half an hour.
What is your opinion on this please?