C8H10N4O2 , or also known as caffeine, is a bitter, white crystalline purine, a methylxanthine alkaloid, and is chemically related to the adenine and guanine bases of our double-stranded genetic material deoxyribonucleic acid (DNA) and single-stranded genetic material ribonucleic acid (RNA).

OK, enough with the biochemical mouthfuls needed for proper introduction. Now let’s talk about some interesting staff.

Caffeine is psychoactive drug that stimulates the Central Nervous System (CNS). In fact, it is the most common psychoactive drug consumed in the world as it is legal and unregulated, unlike other psychoactive substances. It is found in the seeds, leaves, or nuts of a number of plants native to Africa, South America and East Asia, but the well known source of caffeine is in the coffee bean, seed of Coffea plant.

It has a number of uses in the medical world to help treat and prevent a number of medical conditions, but we all know it for its energy boost that it gives us when we drink beverages containing it.

Fun Legend

Legend has it that, in the 19th century, a goat herder called Kaldi found out that his goats were hyperactive and behaving weirdly after eating some berries from a tree. Kaldi was eager to find out what was making his goats so energetic, and he decided to eat some of those berries. His heart started to beat faster, he felt more energized and he could not sleep at night. He then decided to tell the abbot of the local monastery about this, and the abbot came up with an idea: drying and boiling the berries to make a beverage. He soon found out that drinking that beverage kept him and his monks awake, and this was particularly useful when they had to pray at night. Those berries are what today we know as coffee beans.

How Does it Work

The longer we are awake the more a substance called “Adenosine” accumulates in our brain. Adenosine is the waste product of the breakdown of the energy molecules called ATP (Adenosine-Tri-Phosphate).

Adenosine then binds to the adenosine receptors and slows down our brain activity. This will make us feel more tired as we go through the day as more adenosine will accumulate the longer we stay awake.

Caffeine shares a similar molecular structure with adenosine, and this will help caffeine fit perfectly in the adenosine receptor, hence preventing the adenosine to slow down brain activity. It also prevents the reabsorption of a neurotransmitter called dopamine, and this makes you feel happy. This is probably why coffee can be so addictive, just like cocaine (but to a lesser degree).

Caffeine stimulates the production of adrenaline, which plays an important role in the fight or flight response. This will result in an increased heart rate, boost in energy, as well as opening up your airways, dilating your blood vessels, increasing your blood pressure.

The more you are exposed to caffeine the more adenosine receptors your body will create over time, meaning that you will need more caffeine to have the same results. Likewise, if you would abstain from caffeine for a few weeks, the adenosine receptors in excess will disappear.

The Timeline

Once ingested, 99% of the caffeine will be absorbed in your small intestine within 45 minutes entering your blood stream. Peak plasma concentration is reached within 1-2 hours.

In medicine we use the term “half-life” to indicate the time that the body takes to reduce by half the amount of an ingested drug. In case of caffeine, its half-life is approximately 5 hours – so, if you were to ingest 150mg of caffeine, it would take 5 hours for your body to eliminate 75mg of caffeine, and after 5 hours it will eliminate 50% of 75mg, which is 37.5mg, and so on and so forth.

Know the difference

For those of you looking to cut down or cut off their caffeine intake, it is very convenient to go for decaffeinated drinks thinking that they contain no caffeine at all, right? Wrong. Decaffeination process removes around 97% of the caffeine leaving that 3% the chance to still take an effect on your body. This is not really convenient if, like me, you like an after-dinner coffee, and you go for the decaf thinking that it has no caffeine to keep you awake. So, we blame our partner snoring like a tractor if we can’t fall asleep. Whenever you see on the label “decaf“, remember that it still contains caffeine and it carries its potential to knock out the adenosine molecules in your brain If you want to be certain that it does not contain caffeine, then you have to look for “caffeine-free” on the label of the beverage.

Can a caffeine overdose kill you?

Theoretically, the lethal dose of caffeine is 150mg/kg, which means that for an individual weighing 80kg it would take 12000mg of caffeine to kill him/her. A cup of coffee contains approximately 150mg of caffeine, which means that someone would have to drink at least 80 cups of coffee all at once for it to be lethal. It is impossible, because the stomach does not have the capacity to contain 80 cups of coffee, and you would experience delirium and hallucination way before it can kill you. So, the short answer to this question is: No!

Side-Effects of Caffeine

Consuming caffeine within moderate and recommended ranges is good for your productivity and general health. However, as per any other drug, excessive consumption can lead to some side effects:

Insomnia: One of the main reasons of taking caffeine is because it helps us to stay awake and alert when we need to be productive and focused. But too much caffeine can lead to insomnia, which is difficulty in getting enough restorative sleep. This can result in an increased time to fall asleep, disturbed sleep, and either waking up early angry and sleepy, or waking up late angry and sleepy.

Anxiety: The DSM (Diagnostic and Statistical Manual of Mental Disorders) includes caffeine-induced anxiety as one of the four caffeine-induced syndromes. In fact, continuous and elevated doses of caffeine can make you feel nervous or jittery and it can well lead to anxiety.

Digestive problems: Some people find their morning coffee a blessing because of its indirect effect to promote bowel movement. This laxative effect might be due to the release of the hormone “gastrin”, which is secreted by the stomach to speed up activity in the colon. High doses of caffeine though can lead to an excessive peristalsis (the bowel motion that permits the ingested food to move along the digestive tract), that could result in loose stools or diarrhea. Also, it can worsen a condition called gastro-esophageal reflux disease (GERD). It is also important to know that drinking caffeine on a empty stomach is a bad idea as it stimulates the acid productions (which are usually used to digest food) which are too aggressive for the gastric mucosa (internal lining of the stomach).

Addiction: As stated before, caffeine prevents the reabsorption of dopamine, which makes you feel happy – this also happens with cocaine and amphetamines too. This is why caffeine can cause a degree of psychological and physical addiction, but not like the other recreational drugs do.

Hypertension: Albeit temporary, caffeine does have an effect on blood pressure due to its effects on the nervous system. This results in a temporary rise of the blood pressure, which is not really ideal in people who suffer from high blood pressure, and are at risk of cardiovascular diseases.

Tachycardia: One of the many effects of caffeine is to make your heart beat faster. Again, in high doses this can lead to a condition called tachycardia and, as a study shows, it is linked to atrial fibrillation in young individual consuming energy drinks with high doses of caffeine. This effect does not occur in everyone, some people can be exposed to high doses of caffeine with no effect on the heart.

Fatigue: This is quite a paradox since we use caffeine to beat fatigue and boost our energy. However, excessive doses of caffeine can create a rebound fatigue effect that can make you feel more tired than usual the following day.

How to use caffeine to boost productivity

Caffeine can be a great friend when you need a boost of energy to be productive during the day. However, if you don’t know what you are doing and plan your caffeine consumption wrongly, it can be your worst enemy at night, preventing your sleep and affecting your productivity the following day.

So, my advice is: be strategic and do your math.

Try to delay your first caffeinated drink first thing in the morning. High cortisol levels and a good night sleep should make caffein obsolete as soon as you wake up, even though you feel like no one should dare to talk to you before you have finished your coffee. Instead, start your day with a full glass of water to re-hydrate yourself, as well as eating a well-balanced breakfast to start activating your metabolism, this already will give you enough energy to cope with people.

Try not to have high doses of caffeine past 3pm. Remember, your body will get rid of half of the amount ingested in 5 hours, and the last thing you want to happen is caffeine to interfere with the quality of your sleep. You can always choose decaffeinated or small doses of caffeine to maintain the levels of alertness, in this case green tea is a great option. Three cups of green tea replaces one cup of coffee in terms of quantity of caffeine.

You also need to identify when you need to be productive the most. I know that after lunch my energy levels drop drastically and I crave for a nap, but at the same time lunch time is a peak-time for my full-time job and I need all my energies and focus to in order to function. For this reason I try to have a cup of coffee between 11:00am and 1:00pm to keep my energy levels and productivity up for the rest of the afternoon.

How much caffeine is considered “moderate”?

If you made it to this point you have come across some statements like “moderate consumption of caffeine is good for you”, or “moderate consumption of caffeine is not associated with side effects”, and you might righteously starts to wonder “what the heck is moderate?”, “how much is it?”.

Well, the Food and Drug Administrator (FDA), the European Food Safety Authority, and Health Canada reached the unanimous consensus that 400mg/day of caffeine is considered as a moderate consumption, which is not associated with side effects in healthy adults. You can get this amount of caffeine with 4 cups of coffee.

Caffeine containing drinks

Here is a list of some drinks and their caffeine value. The first value in round brackets indicates the serving size, the second value in square brackets indicates the amount of caffeine expressed in mg.

                                            For example: Caffeinated products (ml) [mg]

Starbucks Coffee, Blonde Roast – Grande (470) [360]

Americano – Grande (470) [225]

Mocha – Grande (470) [175]

Espresso (25) [75]

Chai Latte – Grande (470) [95]

Green Tea (236) [35]

Herbal Tea (236) [0]

Pepsi Zero Sugar (590) [115]

Diet Coke (590) [76]

Red Bull (236) [80]

Conclusion

As for everything in life, moderation is the key, and caffeine consumption is not an exception to it. Know how to use it and it can be your greatest friend to help you out, abuse it and it will be your greatest enemy.