Why do we tear up when peeling an onion?

Have you ever wondered why you tear up when your peeling an onion? It hurts and it makes it a harder thing to do when preparing a meal. Onions have a lot of good nutrients that are good for our bodies but when we crush onions we make their tissues release something. Onions release these sulfonic acids and it converts to another type of chemical called the s-oxides. The smell of the onion is usually a reason people think why they tear up with chopping onions but it is the s- oxide that makes a person tear up. The cornea of the eye tries to protect itself from irritating things making the burning sensation happen. Then people start rubbing their eyes to get rid of the burning sensation when it only makes it worse. The onion leaves an odor on your fingers. Closing the eyes is bad idea as well. Some people have suggested heating up the onion before chopping it or lighting a tiny candle before chopping up the onion. It is interesting to see that something everyone always blew off as the smell has a lot of more explanation to it than that. I wonder if anyone would ever go as far as to try to engineer an onion without the oxide that makes us tear up. How would that effect the onion itself?  I know for me growing up with my mom always tearing up chopping onions it made me scared to chop onions or get near them in the cooking sense. I never knew there was an actual scientific reason to people tearing up while trying to chop an onion or even just peeling the outer layer of an onion. I would like to know more about it but unfortunately haven’t found much scientific research on it.



2 thoughts on “Why do we tear up when peeling an onion?

  1. Imaani Allen

    I would so love if someone could create an onion that doesn’t smell and wont make me cry everytime I try to cut it. .When I was younger I hated cutting up onions for my mom because my eyes would burn and get so watery. It was very annoying. I read an article describing some of the health benifits that onion have for humans. I didn’t knwo that oninion have properties designed to prevent certain cancers. All this from a vegtable that smells really bad.


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