Lets try and resolve some caffeine confusion

As I settled down to read the newspaper with (yes) a cup of coffee! An article about coffee caught my eye. "More than four cups of coffee a day increases risk of early death" (check it out and leave your comments).

Again the mysterious cup of coffee causes a stir. 

Drinking coffee is such a prominent part of the modern lifestyle with coffee shops clustering in every high street and our supermarket shelves stacked with all kind of coffee. It surprises me how variant
peoples views are on the effects of this seemingly everyday essential to our health is.


Caffeine is mainly found in coffee, tea, energy drinks, chocolate, cold and flu medicines and surprisingly some caffeine is still found in a cup of decaffeinated coffee (approximately 3.5% of the caffeine found in an non-decaffeinated coffee of the same strength and volume).

Sources of caffeine

Can caffeine be addictive?

Firstly I must define what I am referring to as an 'addictive' substance: a substance which an individual becomes physically and psychologically dependant and has the compulsion to increase the dose of said substance.
Scientists don't class caffeine as an abusive addictive drug. Regular caffeine users may experience a mild physical dependence. Withdrawal symptoms include: headache, fatigue and lack of concentration. However these symptoms may only last a day or so. These symptoms can be reduced is caffeine intake is reduced gradually.
But this still hasn't answered my question as to whether caffeine is addictive?
Well caffeine does not cause severe withdrawal symptoms or the user to exhibit compulsive behaviours as with other drugs. So caffeine is generally not considered addictive, certainly  medically speaking and according to my definition of 'addictive substance'.

Does caffeine cause insomnia? 

It's all about timings....

As mentioned in my previous post caffeine is rapidly absorbed and processed by the body (in about 45 minutes it is distributed to tissues in the body). It takes about 5-7 hours for half of the caffeine to be eliminated from the body (based on dosage from an average cup of coffee). It takes up to 10 hours for 3/4 of caffeine to be eliminated.

So what has this timing got to do with insomnia?

Caffeine is a stimulant so it keeps parts of your brain overactive preventing you from sleeping .

This means that a cup of coffee or two in the morning is unlikely to affect the average persons sleeping habits or consuming caffeine 6 hours before going to bed. However this depends of the individuals sensitivity to caffeine. People who are more sensitive to caffeine may experience insomnia, nervousness and gastrointestinal upset.

Caffeine is known to be a diuretic (it makes us need to pee), consuming a product containing caffeine late at night can mean we won't sleep properly as we keep needing the toilet.

What about increased risk of death?

Caffeine is just a small part of our diet and certainly in small doses it won't impact our health (although a large dose would mean drinking about 100 cups of coffee in a short space of time). Excessive coffee drinking is often linked to other unhealthy habits which may account for the statistics displayed in the article. But remain calm. You're not going to drop dead from drinking another cup of coffee.

Thanks for reading!

Next posts?

I'd like to investigate more of the biological effects of caffeine. And start asking how and why :)

Why does coffee make us pee? How does it mask symptoms of tiredness?