If you've ever had a weird feeling on your teeth after eating spinach, you're not alone. Why must the universe punish us for eating such a healthy food? But don't worry, it's not a punishment—it's actually due to the acids that are found in spinach. I broke it down for you.
The problem
Spinach contains a high amount of oxalic acids. It also has a good amount of calcium. Chewing spinach releases these compounds where they combine in your mouth to form a crystal that doesn't dissolve in water. Then comes the fuzzy coating on your teeth.
Should you be concerned?
If you're worried about these acids eroding your tooth enamel, fear not. The pH of spinach, especially cooked spinach, is so close to neutral that it probably doesn't have much of an effect. And even if it did, the calcium and iron inhibit the acid from reacting with your teeth. In fact, oxalates can actually help reduce tooth sensitivity when included in your diet.
But if you happen to be at a high risk for kidney stones, you'll want to pay attention. Consuming lots of foods with oxalic acids can lead to the formation of calcium oxalate stones. This includes foods like beets, strawberries, teas, nuts and chocolate. By far, spinach has the most oxalic acid, so it should be the food of most concern.
The solution
If you're worried about kidney stones or have seriously thought of giving up spinach to avoid that gross feeling, think again. There are researchers at the University of Arkansas who are working on breeding a variety of spinach with low to no oxalic acid.
For those of us that can't wait to eat spinach until this new variety comes about, there are a few ways you can try to reduce oxalic acid in spinach. The more you cook it, the more neutral the spinach will become, so the less acid there will be in it.
The best solution for raw spinach is to squeeze some lemon juice over top. It'll help dissolve the acid and offset the fact that spinach reduces your ability to absorb iron. Use this as an excuse to make this stellar lemon dressing and keep chowing down on your salad, sans fuzzy teeth.