Speaker 1: Welcome to brain Stuff from How Stuff Works. Hey brain Stuff,
Speaker 1: I'm Lauren Vogelbaum, and today's episode is a brain Stuff classic,
Speaker 1: How does Aspirin Work? I wrote this one for our
Speaker 1: YouTube channel a while back while I was going through
Speaker 1: a pain research phase, which yes, is just about as
Speaker 1: goth as it sounds. It was performed for the podcast
Speaker 1: by our former host, Christian Saga. Let's dive in, Hey
Speaker 1: brain Stuff. It's Christian Sager here. There are lots of
Speaker 1: ways to numb yourself to the minor aches and pains
Speaker 1: that we humans accrew in our daily lives. But today
Speaker 1: we're talking about aspirin. Why aspirin, Because although aspirin as
Speaker 1: we know it has only existed since the late eighteen hundreds,
Speaker 1: the plant that it was originally derived from, willow, is
Speaker 1: probably the oldest known pain killer in history. Records of
Speaker 1: people using willow leaves to relieve pain and fevers stretch
Speaker 1: back six thousand years to ancient Assyria and sumer Willow
Speaker 1: was also put to use in ancient Egypt, Babylon, and China,
Speaker 1: and Hippocrates thought it was pretty rad especially for pain
Speaker 1: during childbirth. In the seventeen and eighteen hundreds, scientists worked
Speaker 1: on identifying, extracting, and purifying the active ingredient in willow,
Speaker 1: which turned out to be a chemical they called salison,
Speaker 1: which they further discovered your digestive system changes into salacilic acid,
Speaker 1: which is what reacts with stuff in your body to
Speaker 1: relieve pain, reduced fever, and swelling. More on how all
Speaker 1: that works In a second, but first salacilic acid. It
Speaker 1: was a pharmacological superstar. German chemists figured out how to
Speaker 1: synthesize it on an industrial scale in the eighteen seventies,
Speaker 1: effectively ending millennia of willow powder use. But it had
Speaker 1: its drawbacks. Lots of patients couldn't stomach it literally, it
Speaker 1: was really hard on the stomach lining The son of
Speaker 1: one such patient, a chemist with Friedrich bear in Company
Speaker 1: by the name of Felix Hoffman, thought it might be
Speaker 1: less irritating if it was less acidic, so Hoffman converted
Speaker 1: it to what bear in Company dubbed aspirin in eight
Speaker 1: Aspirin has become the popular and less ridiculous to pronounce
Speaker 1: name for Hoffman's chemical compound, a setal silic acid or salicylate.
Speaker 1: It works as humanity finally figured out in the nineteen
Speaker 1: seventies by preventing yourselves from using cyclo oxygen ase to
Speaker 1: to create prostaglandins. And don't worry, I'm about to unpack
Speaker 1: all of those words. Let's start with the idea that
Speaker 1: lots of pain is useful evolutionarily speaking, when you feel
Speaker 1: pain due to an injury like a burn or a
Speaker 1: twisted ankle, it prompts you to take your hand away
Speaker 1: from that hot thing real quick, or to keep your
Speaker 1: weight off the ankle until it heals. It's it's useful, right.
Speaker 1: Pain from an injury to anything but the nervous system
Speaker 1: is called no susceptive pain. After specialized sensory neurons located
Speaker 1: throughout your body called no susceptors, They alert your brain
Speaker 1: to damage. With the help of the damaged tissue itself,
Speaker 1: cells in the hurt areas start producing enzymes that work
Speaker 1: together to create a few signal chemicals, including those prostaglandins
Speaker 1: I mentioned a minute ago. Prostaglandins tell your no susceptors, no, hey, seriously,
Speaker 1: there is a problem here. They make your no susceptors
Speaker 1: increase the signal to your brain. You feel the pain
Speaker 1: more acutely now Prostaglandins are also one of the chemicals
Speaker 1: that cause inflammation in the tissue around a wound. They
Speaker 1: make your blood vessels expand, flooding the damaged tissue with
Speaker 1: all the immune systems stuff your body sends to protect
Speaker 1: the wound from infection and to help it to heal.
Speaker 1: All of this is great right up until it isn't.
Speaker 1: After a certain point. You don't need continual acute pain
Speaker 1: as a reminder that you're injured. We know, and some
Speaker 1: non susceptive pain and swelling is warning us about stimuli
Speaker 1: that we can't easily avoid, like headaches, arthritis, or period cramps.
Speaker 1: In the case of arthritis, that inflammation can even cause
Speaker 1: more damage in the long run. Here's where aspirin swoops
Speaker 1: in to save the day. When you take aspirin, it's
Speaker 1: absorbed by your digestive tract into your blood stream, which
Speaker 1: takes it throughout your body, including places where cells are
Speaker 1: excreting the enzymes necessary to produce prostaglandins. Molecules of aspirin
Speaker 1: lock up with one of those enzymes, cyclo oxygenase too.
Speaker 1: Once a molecule of cyclo oxygenase two is locked into
Speaker 1: a molecule of aspirin, it can't help create prostaglandins, which
Speaker 1: means fewer prostaglandins, which means that the pain signals to
Speaker 1: your brain don't increase as much and the tissue in
Speaker 1: the area doesn't swell as much. Hey, thanks thousands of
Speaker 1: years of science. Today's episode was produced by Tyler Klang.
Speaker 1: If you miss Christian and want to hear more from him,
Speaker 1: check out his pop culture podcast super Context, And of course,
Speaker 1: for more on this and lots of other anti inflammatory topics,
Speaker 1: visit our home planet, how stuff works dot com.