Spinach is one of my favorite dark leafy greens, I love it’s soft hearty flavors and I often put them in soups and in stir fry dishes. But what I’m not a fan of is the feeling it leaves in my mouth after I eat them.
Many people have also reported this same thing, the feeling has been described as a chalky or fuzzy feeling. This chalky feeling reminds me of running my nails on a chalkboard and feel a shivering down the spine, just thinking about it conjures up that very uncomfortable feeling.
So why does spinach make my teeth feel funny? I did a bunch of research on this, and the main culprit is a chemical present in spinach called oxalic acid.
What Is Oxalic Acid? What Does It Do?
Oxalic acid are also known as “oxalates,” they’re a chemical that can be found naturally in many different variety of plants and animals. Examples of foods containing oxalic acid include rhubarb, okra, beets, quinoa, soy products, peanuts, cashews, and of course spinach.
But the levels of oxalic acid varies widely in these foods, so not every food containing oxalic acid would give you that uncomfortable chalky feeling. Oxalic acid is considered toxic in very high levels, but these toxic levels are generally not found in spinach and other foods we eat.
But rhubarb leaves on the other hand have oxalic acid levels that are so high that it’s considered poisonous and inedible. Eating rhubarb leaves will make you sick, give you kidney problems and could even kill you.
“Spinach Teeth” – How To Minimize It
The chalky feeling in the teeth after eating spinach is known as “spinach teeth.” When you chew on the spinach, the oxalic acid is released and binds with the calcium present in the body to form calcium oxalate crystals. These crystals stick to the teeth and causes the chalky feeling you get.
My personal experience is that it lasts for about 30-60 mins, during this time if my tongue touches my teeth in any way, a chalky sensation flows through my body and causes an uncomfortable shivering sensation.
Boiling It First
Oxalic acid is water soluble, meaning if you boil it enough you can release the oxalic acid into the water and throw it out.
The downside to this is you lose out all the precious nutrient contents as well when you throw out the water.
What you can do is boil the spinach for about 2 minutes, then pour out the water and put the spinach in a strainer. Run it under some cold water for a minute while squeezing it, this will reduce the oxalic acid some more.
I have tried this method myself and it really does work. But you do have to give it a good boil, I’d say for probably at least 2 minutes.
It wouldn’t work if you just steam it, cause the oxalic acid would still be trapped inside the spinach. The main idea is to dissolve the oxalic acid into the water, and then throw the water away so it doesn’t stick to your teeth when you eat it.
Kidney Stones – Should You Worry?
Although spinach is one of those leafy greens that contain a good amount of calcium at 230 mg per cup, it’s actually a very poor source for it. The reason is because the oxalic acid in spinach is an anti-nutrient, it binds to minerals such as calcium in your body to form calcium oxalate, this interference makes it super hard for the body to absorb the calcium, so most of the calcium is then pretty much useless to the body.
The same calcium oxalate is responsible for about 80% of kidney stones, calcium oxalate is what most kidney stones are made of. But this is not a problem for the majority of healthy people. The important thing to know is that calcium oxalate is produced naturally inside the body regardless of what you eat, it’s totally normal, and it’s usually eliminated out of the body via urine.
But some people in rare cases are more vulnerable to the formation of kidney stones from oxalic acid, and these people should watch their intake of foods that are rich in oxalic acid.
Who Should Be Concerned?
People who have had kidney stones before in the past are at higher risk of developing them again, therefore they should limit their intake of foods that are high in oxalic acid.
Also people with medical conditions such as Hyperoxaluria require them to stay away from oxalic acid rich foods. If you have any sort of medical conditions, I would suggest you to ask your doctor about how much oxalic acid foods you can safely eat.
But for people that are generally healthy, there shouldn’t be any worries about eating certain foods just because they contain oxalic acid. Eating spinach and other dark leafy greens is pretty safe for healthy people. The amount of oxalic acid present in dark leafy greens is not high enough to cause any harm to normal healthy people.
After researching a bunch into this spinach teeth thing, I don’t feel like there’s any reasons to avoid spinach. If you are generally healthy and have no kidney problems, spinach is a great way to eat your veggies.
Even though spinach teeth is annoying, boiling it first can reduce it or eliminate it completely. But as annoying as it is to get spinach teeth, it does go away pretty quickly on it’s own. It’s usually gone within an hour or so, during which time I just try not to move my tongue around too much.
If you have had any experience with spinach teeth, or have any other ideas for getting rid of oxalic acid in spinach, let me know in the comment box below!