Why Does Spinach Leave a Film on Your Teeth?

Published on Thursday, September 17, 2009, by Roxanne Webber / Edit Post

Spinach contains oxalic acid, which is released when you chew it. “When the calcium in your saliva combines with the oxalic acid, calcium oxalate crystals are created,” says Jennifer Moltoni, administrative coordinator at the Department of Oral Medicine, Infection and Immunity at the Harvard School of Dental Medicine.

Because calcium oxalate is not soluble, explains Moltoni, “it deposits on your teeth, which results in the gritty, spinach-mouth feeling.” An interesting note: The sensation worsens if you drink milk while eating spinach, since this introduces even more calcium into the mix.

CHOW’s Nagging Question column appears every Friday. Got a Nagging Question of your own? Email us.

ALLNagging Question
POST A COMMENT |14 Comments

COMMENT

  • OMG!! I thought it was just me!! ...or because of the salad dressing I made :P

    I'm glad I stumbled upon this article! - THANK YOU!!

  • the mystery is solved! i feel that there aren't enough leafy greens available, and spinach is one that when found fresh, looks very yummy. however, i hate that feeling it leaves on my teeth! so lots of olive oil and lemon juice after blanching, eh? thanks!!!

  • Very interesting! I always wondered what the cause of that sensation was. Thanks for the info.

  • Blanching spinach, even for thirty seconds, helps prevent.. I've experienced this many time, and have known others who have also. May it's an individual thing?

  • Note that if you're subject to calcium oxalate kidney stones (the most common kind), spinach is on the top of the list of foods to avoid!!!

  • I have never experienced this, nor heard from someone who has.

  • Interesting... I've never noticed a film on my teeth after eating spinach before. I'll pay attention next time I have some. However, I hate the sticky slime/film I get on my tongue when drinking certain juices, cranberry juice especially. Maybe I'll email and ask about that...

  • thanks :)

  • Acids, like lemon juice, prevent it.

  • haha great how bout BEFORE my guests (and me) get it?

  • brush your teeth

  • ok, very interesting....but how do i get rid of it?

  • I use a lot of butter but I get it. Very interesting

  • I find if you add enough olive oil to a sauteed spinach with garlic, the nasty sensation does not occur. Perhaps i am coating/sheilding my teeth with the olive oil.