You’re at your favorite restaurant, and you’re super excited because the appetizers
have just arrived.
You grab your spoon, ready to dive into your soup -- which is when you notice that there’s
a hair in it.
You have a few different options here:
You could send it back to the kitchen.
You could pick out the hair and eat the soup anyway.
Or maybe… just slurp down the soup, hair and all?
As long as it’s a single strand of hair, it probably won’t do you much harm.
A whole clump would be a lot more dangerous -- that could form a giant hairball in your
stomach and earn you a trip to the hospital.
But in your soup, there’s just one, single hair.
And while it /is/ possible that stowaway bacteria might try and hitch a ride on that hair -- leading
to an upset stomach or diarrhea -- it’s pretty unlikely.
The hair itself is made up of a densely packed protein called keratin.
Humans aren’t capable of breaking down keratin -- instead, small amounts of hair will typically
pass right through your body, along with everything else you can’t digest.
So you could probably take your chances on this lonely hair.
But if the chef whips up a full plate of freshly-cut locks of hair, you might want to seriously
reconsider, because large amounts of hair /will/ get stuck in your stomach.
It happens to cats all the time.
Cats also can’t digest their hair -- or in this case, fur -- and whatever doesn’t
pass through their digestive systems builds up in their stomachs as a firm, dense, hairball,
also known as a trichobezoar.
Eventually, most cats are able to vomit up hairballs before they get too bad.
Humans will also start to develop hairballs if they eat a lot of hair -- which sometimes
happens to people with trichophagia, a compulsion to eat hair.
But instead of being vomited back up, a human’s hairball just sits in their stomach, getting
in the way of everything else their digestive system is trying to do.
In the most extreme cases, the tail of the hairball can reach down into the small intestine,
a condition known as Rapunzel syndrome.
Major surgery is pretty much the only way to get rid of a problem hairball, where the
doctor opens up the digestive tract and pulls out the hairball.
So, all things considered, it’s probably not worth eating a particularly hairy bowl
of soup.
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