The subject of oxalic acid came up in a September 2000 email to Jan Hodges on the Pets pages. Jan researched her herb books and wrote to Mary Wulff-Tilford, co-author of "All You Ever Wanted to Know About Herbs For Pets" (Bowtie Press 1999).

Hello Mary, I talked to you about your book in February. I have since used it many times as a reference, and I really appreciate it. I keep it next to my computer so it is handy when people ask questions. I have a question now. You say on page 24 of your book "All You Ever Wanted to Know About Herbs For Pets" (condensed version) that sheep sorrel may cause kidney stones. I have been hunting for information about this for two years because I am involved with a web page about essiac for pets, and I have heard this before, although only as an assertion, not with any explanation. Jethro Kloss in "Back to Eden" says that rhubarb may cause kidney stones, and that sorrel will aid in expelling them, but he doesn't specifically address the oxalic acid in sheep sorrel. The oxalates in rhubarb really makes sense to me since I have eaten rhubarb pie and it makes the same coating spinach does on my teeth. I can find no other references to this anywhere. Can you give me some more information about this, or a good reference source? Jan Hodges

Mary Wulff-Tilford replied...

Hi Jan, There is a medical book, written by San Diego Medical School (not sure of title or much anything else, this is off the top of my head), that mentions oxalates and kidney stones. As far as I know, it is the only book that has references regarding this. We are of the thought that in small quantities, oxalates aren't going to cause any problems in anyone. I got into a long debate with someone a few months ago, they were saying that Dandelion is high in oxalates and I totally disagree, as do many other herbalists. This person was saying that her dogs had oxalate stones and she would not give them ANYthing that was possibly high in oxalic acid. I just don't agree that this is a problem, especially with dandelion. Now, with sheep sorrel, yes, it's high in oxalic acid, and if eaten in LARGE quantities, could, conceivably, add to or possibly cause stones. However, it would have to be such a large amount (this is my *opinion*, nothing I say here can be quoted as fact) that the person or animal would be very sick and vomiting the substance before stones could form. Let me discuss this with Greg when he returns and we'll see if he agrees or has anything to add... please, give me a day or so to get back with you. Mary Wulff-Tilford, DiHom; Professional Herbalist, AHG Animals' Apawthecary Co-Author of "All You Ever Wanted to Know About Herbs For Pets" Bowtie Press, 1999

Greg Tilford also replied...

Dear Jan, (these are my opinions only) Much of what is said in our book about possible side-effects or contraindications are generalized because the book is written for a very broad audience. The issue of oxalates in connection with urinary stones is generally overplayed. Like most herb related toxicity possibilities, problems almost always are the result of extreme excess. If an animal already has oxalate crystals then it would be a good idea to consider low oxalate options. Spinach is very low in oxalates which taste tangy, like lemon. Rhubarb is very high. Sheep sorrel is somewhere in between. Where an herbal tea like essiac is indicated, at least in our minds, the issue of oxalate crystals relative to long term use, seems way down on the list of health concerns. Bottom line: many, if not most, animals could probably eat a piece of rhubarb pie every week and never develop a problem. If oxalic acid was as big a problem many of the books make it out to be, there would be many humans and animals that have developed side effects. In very wide use, essiac has a well-established track record for safety. Sincerely, Greg Tilford

Editor:  As requested, their thoughts about sheep sorrel and turkey rhubarb will be respected as opinion only, not taken as established fact. Their opinions add much to our understanding.

Note sent by a reader on Feb 7, 2002...

I noticed on your web the discussion about oxalic acid and kidney stones. Dr. Norman Walker, who lived to be 119 yrs old, wrote juicing books and stated that one should never eat spinach, kale cooked as the oxalic acid becomes very harmful and binds with calcium and causes kidney stones etc. But oxalic acid in its raw form is very beneficial to ones health. He said it stimulates the peristaltic motion that moves food through the digestive tract. This is in his book called "Fresh vegetable and Fruit Juices". A health ministry called Hallelujah Acres sells his books.

Kate, who is a Naturopath, wrote on April 6, 2002...

I agree with the comments made by Greg Tilford that appear on your site regarding oxalate acid. As a Naturopath, I recommend that people drink plenty of clean filtered water, up to 3 liters a day (a liter is a little bigger than a quart) whenever they are going through a detoxification of any kind. As the tea is primarily one that detoxifies and cleanses the body it is important to keep water levels up so that toxins are flushed out. In that event, when a person drinks between 2 to 3 liters of water a day, any oxalate acid will be flushed out through the kidneys. If there is a concern, vitamin B6 and magnesium should be taken at the same time so that the oxalate and calcium in the blood do not bind, thus greatly lowering the incidence of stone formation. However, getting an animal to drink lots of water can be a problem, so syringe-feeding the water to them may be needed. Regards, Kate

Evelyn wrote on August 14, 2005...

I have had to have surgery for kidney stones and they gave me a list of things to avoid, because of their high oxalate content. They are beets, beet tops, black tea, chocolate, cocoa, dried figs, ground black pepper, lambs quarters, lime peel, nuts, parsley, poppy seeds, purslane, rhubarb, sorrel, spinach, and swiss chard. Things to eat sparingly are green and wax beans, blackberries, blueberries, carrots, celery, coffee, concord grapes, red currents, dandelion greens, endive, gooseberries, lemon peel, okra, green onions, oranges, orange peel, green peppers, black raspberries, strawberries and sweet potatoes. Since I have been on this diet I have been stone free. I hope this helps someone. There are many kinds of kidney stones. They must be analyzed to find out what kind you are dealing with.

From patient in remission who requests anonymity, on September 15, 2005...

While on a high oxalic-acid diet called "Colonel Joe's Cancer Diet" that was supposed to help cancer patients by "increasing and balancing the needed level of oxalic acid in the blood so the immune system can protect the body from various diseases", cancer spread to my liver anyway and I was given less than 2 months to live. That was in 2002. I stopped the diet because of horrible kidney problems (stones) and its ineffectiveness to kill cancer and I went to Cancer Treatment Center in Tulsa. I underwent conventional treatment along with their supplements and an all organic diet and a supplement called Immune 26. I have been in total remission for over a year, thanks to Cancer Treatment Center doctors and the Grace of God. I was so scared then, now I feel so foolish about that diet decision. But we do stupid things when we're desperate. I don't want others to repeat my mistake. I encourage others to go to Cancer Treatment Center in Tulsa or Chicago or elsewhere in the US. They treat the mind, body and spirit. You see not only conventional doctors, and surgeons, you also see a naturopath, your choice of spiritual leader and a dietitian, plus a whole support team. They encourage balanced healthy eating, no sugar, taking supplements, a positive attitude and most importantly, a spiritual connection. I just received my tumor markers and cat and pet scans and I'm still totally cancer free as of September 15, 2005. Plus my horrible kidney stones are gone! I did not have to have surgery to have my breast removed because I had total resolution of cancer in breast (2 14cm tumors) and 6 tumors in lymph nodes, plus resolution of cancerous tumors on my liver. I did one year of chemo and 2 months of radiation, but along with that I did the organic diet, noni juice, supplements, and a wonderful product called Immune 26. I worked everyday, even after chemo and radiation. I went through the procedures just fine. Again, thanks to the guidance of great doctors and the Guidance and Grace of God, I'm still here. After being at death's door because of too much oxalic acid, I strongly advise healthy people and cancer patients to stay away from such diets.