How Caffeine Works in Your Body

By far the most popular stimulant drug in America is caffeine. It helps us wake up in the morning and stay awake during the day. Sadly, many of us ‘need’ it because we don’t get enough sleep, but that’s another issue. We know it works, but often we don’t know how caffeine works. It’s in all sorts of drinks like soda, coffee, tea and energy drinks. And we don’t often pay attention to how much we consume either. In fact, there is 100mg in a typical cup of coffee, 75mg in instant coffee and 50mg in the average tea.¹ It is recommended that we get a maximum of 400mg per day. Exercisers are probably OK with a little more, but this much is found in 4 cups of coffee, 10 sodas or about 2 energy drinks. Of course, these amounts are only estimates; products will vary.²

The Side Effects of Too Much Caffeine

Getting too much can cause a condition called caffeinism. It will make you feel restless, agitated and excited.¹ It will then turn into rambling thoughts and speech as well as insomnia. Plus, you might feel anxious, experience eating disorders and have trouble sleeping normally. Some caffeine is fine, although usually not within 4-6 hours of bedtime, but be aware and limit your intake to avoid these nasty side effects.

How Caffeine Works in Plants (Where it Comes From)

The chemical name for caffeine is 1, 3, trimethylxanthine, but we’ll stick with caffeine.’ It naturally occurs in the seeds or leaves of plants. The content varies widely among different plants, but the most well-known are the seeds of the coffee plant. Its purpose is a deterrent to bugs. Caffeine often messes up insect chemistry and thus keeps them away, but in humans it causes stimulation of the brain.^3,4

How Caffeine Works in Your Brain?

You certainly already know that caffeine makes you feel more alert, awake and perhaps focused. The reason for this that its structure is very similar to that of two chemicals. First, adenosine and second, cyclic adenosine monophosphate (cAMP for short), which is essentially how caffeine works as you will see. Adenosine attaches to brain cells and causes certain effects, namely fatigue. As more and more builds up in brain cells, you become more and more tired. Normally, when you sleep, this adenosine is cleared away. But caffeine has a similar effect. Since it ‘looks’ so much like adenosine, it can bind to the receptors on brain cells that are normally reserved for it. If the caffeine is binding it, then adenosine can’t. Thus, you don’t feel tired.

Caffeine and cAMP

cAMP is a chemical messenger that helps regulate blood pressure and oxygen levels. This is particularly important in the brain as higher oxygen and higher blood pressure deliver more nutrients, more quickly and allow the brain to function at its best. To counteract this so that pressure and oxygen level don’t get too high, our bodies make something called cAMP-PDE. This breaks down cAMP and eliminates its effects of increasing blood pressure and oxygen level.. Because of its structure, caffeine hinders this enzyme. Since it can’t eliminate cAMP, at least for a while, your blood pressure increases and more oxygen makes it to your brain cells. Of course, this means that you feel more energetic and alert.

A Last Word

There are lots of other benefits to caffeine as well. Although I won’t go into the biological reasons for each, it does a lot of good. Again, you don’t want to overdo caffeine because too much can have some nasty side effects. But here is a list of additional benefits⁵: