How long does caffeine work?

There is great individual variation in how we respond to caffeine. Some people claim that they can not sleep after drinking coffee as early as 12 o'clock in the morning. Can caffeine really have an effect for that long, or is it imagination?

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Some people can apparently drink one cup after another just before bedtime without it causing any problems at all. Others cannot sleep, even though it is many hours since they drank the last cup.

Why is there a difference? 

A lot of people are incarnated coffee drinkers and pour in almost unimaginable amounts every single day.

Some people can apparently drink one cup after another just before bedtime without it causing any problems at all.

Others cannot sleep, even though it is many hours since they drank the last cup.

I has previously written about the health benefits of caffeine and how different people have different tolerance for caffeine.

But can there also be individual differences in the breakdown of caffeine and how long does it take before the effect of the caffeine disappears?

Half-life of five hours

I passed the question on to Olav Spigset, who is a professor at the Department of Laboratory Medicine, Pediatrics and Gynecology at the Norwegian University of Science and Technology (NTNU).

He explained that caffeine can ruin sleep in several whimsical ways.

In pharmacology and chemistry, people talk about the half-life. This is the time it takes before the concentration of a substance is reduced by half.

One more half-life – and the amount of substance is halved once again through decomposition or excretion from the body.

Olav Spigset explains that the half-life of caffeine is about five hours.

“It takes an average of five hours before caffeine levels are halved. 10 to 15 hours later, there is so little caffeine left that it no longer has an effect. “

Olav Spigset says that caffeine still has a stimulating effect, despite the fact that the level has halved. In some people, the half-life is either shorter or longer. He elaborates:

‘A half-life of five hours is the average in the population. But in some people, the half-life of caffeine is as low as an hour and a half. Among people who have a slow breakdown, it can be up to 10 hours, “he says.

»So if you drink a cup of coffee at 12 in the morning, you may have trouble sleeping if you go to bed at 10-11 in the evening, because some people still have so much caffeine in their body that it is difficult to sleep due to the invigorating effect. “

Birth control pills and smoking can also have an effect

It is the amount of enzymes in the liver that determines how quickly the caffeine is broken down.

Enzymes are proteins that are found in innumerable variations in the body and they are of great importance for all the different chemical reactions that take place.

‘Caffeine is broken down in the liver by special enzymes. The amount of these enzymes can vary from person to person. Different drugs can also affect the degradation, “explains Olav Spigset.

“Certain drugs can speed up the breakdown, so you need to drink more coffee to achieve the stimulating effect. Other drugs can block the breakdown of caffeine. “

He also says that women who are pregnant or taking birth control pills have a slightly slower breakdown of caffeine. Therefore, they may experience a higher concentration of caffeine in the body, which can lead to unwanted side effects such as muscle turmoil, chills and palpitations.

‘Smokers often break down caffeine faster than non-smokers. If you smoke, you need more coffee to have the same invigorating and stimulating effect. If you stop smoking, the breakdown starts to happen more slowly again, “explains Olav Spigset.

“Many former smokers find that they can not tolerate drinking as much coffee as before, and they often automatically reduce their coffee intake to avoid overdosing,” he continues.

How much caffeine in a cup of coffee 1

Individual differences in caffeine tolerance

Olav Spigset explains that there are also individual differences in caffeine tolerance.

»Caffeine affects certain receptors in the brain. The receptors are almost like small keyholes, and the caffeine is like small keys, so when the caffeine stimulates the receptors, it triggers a stimulating effect on the brain.

“If these receptors are stimulated a lot and often, they gradually become less sensitive to caffeine, and thus a tolerance development occurs; that is, a less stimulating effect of the same amount of coffee, “says Olav Spigset. He continues:

»If caffeine is consumed regularly, for example as coffee for a long time, and you stop drinking coffee, so-called withdrawal symptoms can occur. This can happen, for example, if you are used to drinking a lot of coffee at work, but do not drink as much coffee at home on the weekends. “

The withdrawal symptoms are usually harmless – such as headaches. But these are the same principled, underlying mechanisms that are found in caffeine abstinence as in abstinences after abuse of hard drugs, Olav Spigset explains.

Facts

Caffeine – C8H10N4O2

Caffeine is a white substance with a bitter taste.

Caffeine is found in coffee beans (1-1.5%) and tea leaves (up to 5%) as well as in a number of other natural products (including cocoa and cola). 

The compound is extracted from tea, among other things, but can also be synthesized from uric acid and urea.

Taken as a medicine for headaches in doses of 50-100 mg equivalent to a regular cup of coffee, caffeine has a weak stimulating effect on the central nervous system. 

Larger doses can cause insomnia, muscle turmoil and palpitations , but fatal poisonings are not known. 

With sudden cessation after prolonged ingestion of large doses, mild withdrawal symptoms may be seen.

Caffeine is doped , but the permissible urine concentration (12 μg / ml) is not exceeded by regular consumption of coffee or cola.

Stimuli - for better or worse

Olav Spigset points out that the amount of caffeine that you consume obviously affects the effect your experience – even though the half-life of the caffeine itself is the same.

»Cola and tea contain less caffeine than regular coffee per deciliter. Energy drinks contain just under the same as coffee per deciliter, but we often drink more energy drinks at a time than coffee, «says Olav Spigset.

He adds that it may be due to some very undesirable effects – especially among children and adolescents who have not normally developed tolerance to caffeine.

So it seems that the colleague is right when he or she says no thanks to the afternoon coffee due to sleep problems.

Caffeine is a substance that can stimulate us for better or worse.

‘There is, of course, always a placebo element in the subjective perception of things; such as not being able to sleep. But caffeine has a very real physiological effect on sleep, «concludes Olav Spigset.