Popularized by the classic cartoon show “Popeye the Sailor Man,” spinach is a dark and leafy green vegetable packed with vitamins and nutrients. It’s a superfood with a wide range of health benefits, like being the best source of dietary calcium, magnesium, and potassium. It provides tons of nutrients essential for bone, skin, and hair health.
Spinach can be incorporated very easily into dishes because it cooks quickly. However, what you won’t like about it is that it leaves a strange film on your teeth or roof of your mouth. You know it – it’s something fuzzy, dry, and chalky. This weird phenomenon is called “spinach teeth.”
Where Does Spinach Teeth Come From?
Spinach is rich in calcium, and the insoluble form of oxalic acid. Other green leafy vegetables also contain this oxalic acid, which binds calcium and iron. It leads to the reduced absorption rates of these minerals in the body. Even though spinach is high in calcium and iron, the high amount of oxalic acid inhibits the body’s absorption of these minerals at the same time.
Oxalic acid is a naturally occurring vegetable found in many plants, but spinach tends to have higher amounts of this substance. When still planted, Spinach uses the acid as a natural defense mechanism against insects and animals that may try to eat it.
Besides spinach, here are other foods high in oxalate:
- Dry beans, except lima and green beans
- Sweet potatoes
- Soy milk
- Wheat bran
- Collard greens
- Black tea
As you chew spinach, the calcium in the saliva interacts with oxalic acid that forms calcium oxalate crystals. These crystals are tiny and float around in your mouth, giving that fuzzy, gritty feeling that also leads some people to characterize spinach as a bitter green. Calcium oxalate crystals are nearly insoluble in water, so it ends up in kidney stones for people who are prone to developing it. So, if you have the tendency to form kidney stones, talk to your doctor as it is best to avoid foods rich in oxalic acids.
Spinach is filled with other compounds too – like beta carotene, folate, vitamin C, iron, lutein, potassium, and phosphorus – that can also cause spinach tooth.
How to Minimize the Fuzzy Feeling
You can’t completely avoid the weird film that spinach can make you feel in your mouth, but you can minimize it. When you eat spinach mixed with something else (like in a salad or as a pizza topping), you won’t feel it that much.
The oxalic acid in spinach prevents the body from absorbing iron, so to improve it, eat spinach with foods that contain vitamin C. Squeezing a fresh lemon on top of raw spinach leaves can help.
Also, spinach lovers tend to boil or steam the vegetable to help get rid of calcium oxalate. You will still ingest the oxalic acid when you eat spinach with lemon or other vitamin C-rich fruit and vegetable, but it can reduce the film you can get on your teeth.