Some people on the raw food diet express concern about consuming excess quantities of oxalic acid from sources such as spinach, swiss chard and beets.
There is a big difference, however, between cooked and raw forms of oxalic acid. When cooked, it is not actually a nutrient in the body, so the body naturally processes it into the most convenient form to be excreted, usually through the urine. Oxalic acid will combine with other substances during this process and forms a salt known as an oxalate. Oxalates are believed to contribute to the formation of kidney stones. They combine with calcium to form calcium oxalate. Kidney stones are 70-90% calcium oxalate.
These stones accumulate and get lodged in the urinary tract. Consumption of animal protein and an acid producing diet is also associated with oxalate production, because they cause the blood to become too acidic.
Since calcium is an alkaline mineral, the body will leech it from the bones to equalize the pH balance in the blood. The remaining calcium is eliminated through the urine in the form of calcium oxalate. If levels are high enough, the calcium will crystallize and form small clumps that become stones. A raw food diet can be an invaluable aid to alkalize the blood.
Addressing this subject from his book “Conscious Eating”, Dr. Gabriel Cousens says “Organic oxalic acid, defined as that which occurs in nature in its raw form, can actually be beneficial to the system.
Once foods containing oxalic acid are cooked, according to the dean of juice therapy and author of Raw Vegetable Juices, Dr. Norman Walker, the oxalic acid becomes dead and irritating substance to the system. He feels that in its cooked form it binds irreversibly with the calcium and prevents calcium absorption. An excess of cooked oxalic acid may also form oxalic acid crystals in the kidney.
Dr. Walker claims that in the live organic form oxalic acid does not present any problem. Oxalic acid stones and calcium blockage do not occur because the organic oxalic acid can be metabolized appropriately. According to Dr. Walker, oxalic acid in its raw form is one of the important minerals needed to maintain tone and peristalsis of the bowel.”
If kidney stones are a concern to you, first of all, be sure to work with a natural health practitioner that you trust, preferably one who is familiar with and supportive of the raw food diet. Secondly, eliminate salt, even Celtic sea salt, from your diet as much as possible! Salt is a constant irritation to the renal system.
Also, make sure you are eating a wide variety of alkaline foods, which you will accomplish quite easily simply by adhering to a raw foods diet.
Be sure to rotate your greens in juices, smoothies and other recipes to make sure that you are not taking in excessive amounts of any one substance, but rather moderate amounts of a wide variety of nutrients.
Alternate between raw foods that are high in oxalic acid, and those that aren’t. When you have eaten and enjoyed one type of green for a while, switch to something else. This is not only healthy, but has the added benefit of keeping your diet interesting, too. Of course, these suggestions are not just for those concerned about kidney stones, they are valuable to everyone who practices the raw food diet.
Variety is the spice of life….enjoy!