My daughters and I have really gotten into green smoothies this summer.  We love trying all different combinations – both those that are tried and true and others that are a bit more “unique.”

While researching new recipes for us, I have frequently come across articles warning of the dangers of excess oxalic acid.  Excess oxalic acid can interfere with calcium absorption and lead to the development of kidney stones.

According to the research (click here for article) the levels of oxalic acid in vegetables is dependent upon several variables, but some of the foods that are high in it are spinach, collard greens, and Swiss chard.  These are three veggies that we frequently use in our smoothies.

Luckily, there is a solution as either steaming or boiling the vegetables decreases their amount of oxalic acid.  You do want to make sure to rinse them and toss out the water they were boiled in to get rid of the oxalic acid.

We have a bit of a backlog of greens, so I was planning on boiling some of ours and then freezing them in serving size packages to use in our smoothies.  Since the fruit in the smoothie masks a lot of the taste of the greens, I don’t think boiling will have any big effect on the taste.