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Why Do Onions Make You Cry?

Vegetables don’t make you cry? I’ll bet they would if you were chopping onions!

Hey, kids I’m Professor Motti Maven, Thinker, Wonderer, and Figure-Outer of all things science-ish. What that basically means is I try really hard to figure stuff out

Let me share something personal with you people. Recently, I was in my kitchen sobbing. Not because I stubbed my toe. (Although I did. Ouch!) I was weeping over my vegetables. What? Vegetables don’t make you cry? I’ll bet they would if you were chopping onions!

When I finished sobbing and sniffling, I wiped my eyes and got to thinking.


Why do onions make you cry?

First of all, I have to admit that I don’t actually know why anything makes you cry. Honestly, we’ve just met and I don’t know you that well. Maybe you were really friendly with that onion and you didn’t want to chop it? Maybe you really wanted to be slicing celery? Maybe you’re overly sensitive about plants in general?

But maybe none of those are true and you’re still crying anyway. In that case, you’re just like me and lots of other people who get teary when we chop onions.  If you’re really like me, you’re also wondering why this happens. Lucky for you, I did a little research and I think I have the answer you’re looking for!

Onions are part of the Allium family of plants, along with garlic, chives and leeks.  There are lots of different types of onions, like yellow onions, pearl onions, white onions, red onions (which are actually pretty purple!) and Vidalia onions. But here’s something they all have in common: they all get their strong, oniony taste from the sulfur that they absorb from the soil as they grow. Onions also contain an enzyme called synthase. The sulfur and synthase are stored in different parts of the plant and they usually live together in peace and harmony, but when you cut into an onion, the cell walls rupture and the synthase and sulfur react with each other to form a new chemical compound called syn-Propanethial S-oxide. (Try saying that three times fast without crying!)

Syn-Propanethial S-oxide forms a gas that floats into the air and gets into your eyes. Then your brain tells your tear glands to respond by producing tears to flush this gas out of your eyes. Your eyes listen to your brain, because, well everyone knows he’s a smartypants.

So are you doomed to go on wailing and weeping? Is there anything to be done about this awful sniffling and sobbing?

(Excerpted from Mishpacha Jr., Issue 791)

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