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  • Millions of Americans use caffeinated beverages every day as a pick-me-up.

  • It is, after all, the world's most popular drug.

  • And with new caffeine infused products like energy drinks, gum, and even beef jerky hitting the shelves,

  • our love affair with caffeine shows absolutely no signs of slowing down.

  • Caffeine is an interesting drug because when it enters the body it breaks up into three different yet very similar molecules.

  • When metabolized in the liver, enzymes chisel off one of three methyl groups to form these three metabolites with three different effects on your body:

  • Theobromine, paraxanthine, and theophylline.

  • While in the brain, this caffeine party crashes adenosine receptors, blocking the normal guest, adenosine, from doing its job.

  • Adenosine is responsible for slowing down nerve activity in your brains, giving us the cue to calm down and take a nap.

  • Also, adenosine is responsible for regulating neurotransmitters in the brain such as dopamine.

  • As you can see, adenosine is also quite similar to caffeine in structure,

  • which is why caffeine binds so easily to the adenosine protein receptors.

  • Once connected, caffeine increases the activity in neurotransmitters like dopamine,

  • ultimately leading to heightened brain activity.

  • Then, the three metabolites perform their own specific functions.

  • Theobromine increases oxygen and nutrient flow to the brain.

  • Paraxanthine enhances your body's athletic performance by increasing the rate of fat breakdown to fuel muscle activity.

  • Theophylline increases your heart rate and reinforces your ability to concentrate.

  • And, although these effects come together to produce a state of wakefulness,

  • too much caffeine can turn sour pretty quick.

  • At higher doses, caffeine is known to cause jitters, anxiety, and just general all-around discomfort.

  • For this reason, scientists have found that four hundred milligrams is the safest average dose of caffeine for adults.

  • To put that into perspective, that'll be around three eight-ounce cups of coffee,

  • five eight-ounce Red Bulls, or a whopping eight cups black tea.

  • And on a side note, scientists have also found that caffeine becomes toxic around 10 grams,

  • which works out to be about seventy five cups of coffee, or 180 cups black tea.

  • However, the lethal limit does vary widely from person to person.

  • Hey, thanks for watching folks.

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Millions of Americans use caffeinated beverages every day as a pick-me-up.

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