We love greens and have made a commitment in our household to grow them abundantly in our garden and to eat them with relish. However, when we are consuming greens in quantity, particularly in dishes like our extra-green soups, we do pay attention to the content of oxalic acid in them. Oxalic acid will reduce your digestion on minerals such as calcium and iron; it can also give you kidney stones. Spinach, collards, and lambs quarters have enough oxalic acid that we do take care to reduce it with boiling. (Read more about calcium and oxalic acid on our partner site.)
Thank you for such an informative article (on your partner site). Do you know if there is a reliable source to purchase fermented carrots and other vegetables?
Also, do you think it is possible for my body not to be absorbing magnesium because I’m eating too many raw carrots and spinach that hasn’t been prepared properly?
Michele — You’ll still get minerals out of the carrots and spinach and you’ll get minerals as well from the rest of your food. Do you have symptoms of a magnesium deficiency?
No, I don’t think I have symptoms of a magnesium deficiency. I am just concerned/confused about getting the most nutrient absorption out of my food. I have been reading so many things about oxalates and phytic acid, but I don’t have time to soak, sprout, and/or ferment everything. I also don’t want to do more harm than good by eating too many high oxalate veggies, but at the same time want the nutritional benefits of greens, etc.
One more question…
I was considering taking a magnesium oil supplement, but read that it interferes with calcium absorption. Do you have any suggestions for achieving the proper balance–preferably through food and not supplements?
Thank you for your time.
Just wondering. Is it ok to drink the liquid that the vegetable is boiled in or will that contain the oxalic acid? I was thinking about boiling say spinach in bone broth then drinking that.
The oxalic acid will end up in the bone broth. It’s hard to say — if you’re drinking a lot or really prone to kidney stones, I’d boil it in water and then add the vegetable to the broth afterwards. If you’re just having some greens in soup, I wouldn’t worry about it.
Do you know how long they have to be boiled to achieve the decrease in oxalic acid? I can’t stomach kale that’s too boiled, I usually lightly steam until it’s bright green and still a little crispy.
Very good to point out that boiling certain vegs will reduce oxalic acid. Thanks for sharing especially the fact that I just mentioned. Keep up the good work
Here’s the problem with cooking. Though there are numerous benefits to cooking, there are also drawbacks. Cooking kills probiotics, destroys enzymes, and degrades nutrients. Has anyone ever done a cost / benefit analysis of cooking various vegetables?
I haven’t seen one. My approach is to eat both. For the oxalic acid, I only boil lamb’s quarters because it is high in oxalic acid and we eat large quantities in our soups.