# Spinach makes my teeth feel gritty? **URL:** \ **Category:** Factual Questions\ **Created:** [January 12, 2003, 6:44pm UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165 "2003-01-12T18:44:29Z")\ **Posts on this page:** 8\ **Page:** 1
**Author:** ![SandWriter](https://avatars.discourse-cdn.com/v4/letter/s/8491ac/32.png) [@SandWriter](https://boards.straightdope.com/u/SandWriter)\ **Post date:** [January 12, 2003, 6:44pm UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165/1 "2003-01-12T18:44:29Z")
Hey All, We had some spinach cooked in olive oil and after eating it my teeth felt weird, kind of gritty. I remembered that eating spinach would always leave my teeth feeling gritty. I checked google and there was a site that mentioned spinach lacked oxalic acid or something to bind to iron?, it didn’t make any sense to me? Thanks, -Sandwriter ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [January 12, 2003, 6:54pm UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165/2 "2003-01-12T18:54:00Z")
Spinach also tends to grow in sandy soil, so if it’s not washed properly, that gritty feeling you have _could_ be sand. ---
**Author:** ![Tansu](https://avatars.discourse-cdn.com/v4/letter/t/67e7ee/32.png) [@Tansu](https://boards.straightdope.com/u/Tansu)\ **Post date:** [January 12, 2003, 6:58pm UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165/3 "2003-01-12T18:58:20Z")
Yes, sometimes there is sand left on the spinach if it isn’t washed properly. But I think that the “kind of gritty” that the OP is talking about is a weird, furry, almost suede-y feeling on the teeth when rubbing top and bottom teeth against each other after eating spinach. I’ve experienced the feeling, but unfortunately I don’t know what causes it. ---
**Author:** ![Qadgop\_the\_Mercotan](https://sea3.discourse-cdn.com/straightdope/user_avatar/boards.straightdope.com/qadgop_the_mercotan/32/83_2.png) [@Qadgop\_the\_Mercotan](https://boards.straightdope.com/u/Qadgop_the_Mercotan)\ **Post date:** [January 12, 2003, 7:15pm UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165/4 "2003-01-12T19:15:06Z")
Is it the same sort of gritty feeling one gets on one’s teeth after vomiting bile? ---
**Author:** ![astro](https://avatars.discourse-cdn.com/v4/letter/a/9dc877/32.png) [@astro](https://boards.straightdope.com/u/astro)\ **Post date:** [January 12, 2003, 7:22pm UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165/5 "2003-01-12T19:22:09Z")
It’s not complicated. The oxalic acid in spinach (which becomes much more available if it is throughly cooked ) slightly etches the tooth surface and it feels “fuzzy”. Oxalic acid also prevents the uptake of iron and calcium so megadoses of cooked spinach are not a great idea. Everything in moderation. [Rec.food.cooking](http://groups.google.com/groups?q=spinach++acid+oxalic+teeth&hl=en&lr=&ie=UTF-8&oe=UTF-8&selm=4tuu2b%24rsl%40kaiwan.kaiwan.com&rnum=3) > [@](#): > > Rhubarb and strawberries, as well as spinach, sorrel, and other greens derive tartness and that feeling that something is clinging to your teeth from the traces of oxalic acid that they contain. [Oxalic Acid](http://groups.google.com/groups?q=spinach++acid+oxalic+teeth&hl=en&lr=&ie=UTF-8&oe=UTF-8&selm=AkBE7.115130%24My2.64517777%40news1.mntp1.il.home.com&rnum=5) > [@](#): > > Oxalic acid is available in paint stores. It is used to bleach wood. It is about the only reagent that can dissolve rust and rust stains. It is a common dye mordant, especially useful with vegetable dyes. (Note vivid colors of Guatemalan weavings.) Spinach has a lot of iron, but it is not a very good source of dietary iron. It’s high oxalic acid content sequesters the iron and makes it unavailable for absorption. ---
**Author:** ![Squink](https://avatars.discourse-cdn.com/v4/letter/s/b5e925/32.png) [@Squink](https://boards.straightdope.com/u/Squink)\ **Post date:** [January 12, 2003, 7:56pm UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165/6 "2003-01-12T19:56:20Z")
Here’s an old thread with more on the effects of oxalic acid in spinach: [My teeth’s got dry finish, cuz I eats my spinach](http://boards.straightdope.com/sdmb/showthread.php?s=&threadid=121363) ---
**Author:** ![SandWriter](https://avatars.discourse-cdn.com/v4/letter/s/8491ac/32.png) [@SandWriter](https://boards.straightdope.com/u/SandWriter)\ **Post date:** [January 12, 2003, 8:56pm UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165/7 "2003-01-12T20:56:56Z")
Okay, I admit I missed Squink’s previous thread. I searched on “teeth spinach” before I posted, maybe I didn’t go back far enough, I thought I hit the ‘any date’ option. Thanks for the responses. -Sandwriter p.s. I was talking about the oxalic acid etch on the teeth, and not the sandy crunch of unwashed spinach. ---
**Author:** ![antechinus](https://avatars.discourse-cdn.com/v4/letter/a/fbc32d/32.png) [@antechinus](https://boards.straightdope.com/u/antechinus)\ **Post date:** [January 13, 2003, 3:00am UTC](https://boards.straightdope.com/t/spinach-makes-my-teeth-feel-gritty/148165/8 "2003-01-13T03:00:27Z")
I always thought that the astringent mouth-feel produced was due to the reaction of the oxalic acid with proteins in the saliva. The slipperyness of the tounge over the teeth is due to the lubricating effect of the saliva. When the lubricant properties are broken down the teeth feel ‘gritty’ or ‘squeeky’ to the tounge.