Caffeine is the world’s most popular psychoactive drug. It’s also one of the most addictive substances in the world. Almost two thirds of American adults drink coffee on a daily basis. Other forms or caffeine intake are through tea, energy drinks, soft drinks, chocolate, weight-loss pills or supplements.

But what effect does caffeine have on our brain and body? Is it harmless or should we limit our daily intake?

How Does Caffeine Affect Our Brain And Body?

One of the most important effects that caffeine has on the brain is that it blocks the effect of adenosine; a chemical which is involved in making you sleepy. Normally, when adenosine builds up during the day and reaches a certain concentration in the brain, it will cause our heart rate to drop, and to make us feel tired. It’s our cue to get some sleep. Caffeine blocks the adenosine receptors in your brain, preventing adenosine from carrying out its sedative effect.
Over time, caffeine consumption may increase the number of adenosine receptors in the brain. This causes us to become tolerant to it’s effects. And thus needing a higher daily intake.
Up to four cups of coffee (400 mg) per day is thought to be safe for most healthy adults. Adolescents, however, should not have more than 100 mg a day. Which isn’t a lot if you consider that Red Bull contains about 80 mg and a can of Coke contains 34 mg.

The Bad And Ugly Sides Of Caffeine

When consuming more than the suggested amount, caffeine can cause dehydration, muscle tremors, nervousness, dizziness, heart rhythm disturbance and an upset stomach. Plus, caffeine can disturb sleep rythm, even in moderate doses. The effects of caffeine can take up to 6 hours to wear down. Making it difficult to fall or stay asleep long after you had your tasty cappuccino.
Furthermore, caffeine has an influence on cortisol levels. Also known as the ‘stress hormone’. It causes a solid increase in cortisol levels in those who aren’t regular coffee-drinkers. High levels of cortisol can lead to alterations in the reaction to stress, a disturbed sleep rythm, excess fat storage and an increase in appetite.

The Good

Although caffeine tends to have a bad reputation, it also has major positive effects on the brain and body. Caffeine is thought to have a positive effect on heart health; lowering the risk of heart attacks and strokes. Another positive effect is that caffeine intake increases cognitive control, resulting in better performance on cognitive tasks.
Furthermore, caffeine is argued to have a positive influence on the onset and progression of Parkinson’s disease. It could improve motor deficits as well as non-motor deficits (like memory and emotional functioning). This is remarkable since non-motor deficits do not improve with the current anti-Parkinson’s drugs.
Caffeine also has a positive effect on memory. It can enhance memory consolidation, which is the storing of memories in our long-term memory.

Caffeine Sensitivity

Not everyone has the same reaction to caffeine. Some cannot live without it, while others feel jittery, nervous and dizzy after just one cup of coffee. How is this possible? Reseachers discovered that caffeine sensitivity is captured in our genes. The gene CYP1A2, to be precise. Version 1 of the gene causes a quick caffeine metabolization. When someone inherents two copies of the ‘quick’ variant, they metabolize caffeine fast. They are able to splurge on caffeine without feeling much while slow metabolizers tend to be hypersensitive to caffeine.

With so many positive as well as negative effects, researchers have simply not determined if caffeine is a blessing or a curse. What do you think?

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