All About Oxalates with Susan Costen Owens

by Joanne

in Problem Foods

If you’ve been following mainstream nutritional advice on what vegetables are healthy, or if you’ve been consuming a vegetarian diet for years, you might be getting a high dose of oxalates in your diet. Spinach, chard, mesculin greens, beets, wheat, buckwheat, millet, almonds, sesame seeds, chocolate, carob, tea, and soy milk are all high-oxalate foods.

Conditions that could cause oxalates to build up in your body include leaky gut, poor fat digestion, chronic diarrhea or constipation, and use of antibiotics causing destruction of gut bacteria. A buildup of oxalates in the body interferes with many metabolic processes and contributes to problems such as autism, ADD, COPD, asthma, cystic fibrosis, vulvodynia, autoimmune diseases such as fibromyalgia and hypothyroidism, low energy, chronic pain, and delayed healing of injuries. Oxalates also interfere with the absorption and regulation of calcium.

Oxalate is an antinutrient that is present at higher levels in some plant foods like spinach, nuts, and chocolate, but it is also a mitochondrial toxin and neurotoxin, and impairs calcium and iron regulation, all biotin-dependent enzymes, and many other enzymes. — Susan Costen Owens

In this interview we discuss oxalates in detail and how they affect cell biology. Learn how reducing oxalates in your diet may help you improve your health and energy levels, heal chronic injuries, reduce symptoms of autism, eliminate kidney stones, which simple mineral you can add to your meals to bind oxalates and prevent their absorption, which vitamin and herb in high doses can increase oxalates in your body, and the role of gut bacteria in metabolizing oxalates.

The good news is that many have found that once they reduced their bodily burden of oxalates, foods they were previously sensitive or allergic to no longer caused problems and could be eaten again.

Total time: 67 minutes.


Click to listen to part 1 of this interview or right-click to download MP3 file.

Click to listen to part 2 of this interview or right-click to download MP3 file


Susan Costen Owens has lectured widely, both nationally and internationally. This graduate of Vanderbilt University with a masters degree in Interdisciplinary Studies from the University of Texas in Dallas has fifteen years of experience in autism research. She realized six years ago that the gut inflammation and leaky gut in autism and other developmental disorders would lead to increased absorption of oxalate from the diet with unknown consequences. Through her project at the Autism Research Institute, this diet has led to the loss of the autism diagnosis in some children and improvements in pain, cognition, growth, motor skills, gastrointestinal function, and social interaction in countless others. Her internet group, Trying Low Oxalates, has grown to more than 3000 people, including those with celiac disease, cystic fibrosis, myotonic dystrophy, Rett syndrome, MHE, bariatric surgery, short bowel syndrome, chronic pain syndromes like fibromyalgia, vulvodynia and bone pain, chronic fatigue, autoimmune conditions, and many other conditions, taking the study of oxalate’s relationship to disease far beyond the familiar turf of kidney stone disease.

Links in Interview

The Low Oxalate Cookbook: Book two
Low Oxalate Diet Website
The Vulvar Pain Foundation
How to Dissolve Kidney Stones YouTube video

{ 20 comments… read them below or add one }

Phyllis Stephenson

This is nuts. ( or no nuts, per se). But I was dx’d w/ a pituitary tumor, which caused low HGH (maybe caused by a vehicle accident); however, I also had hypothyroidism, after a thyroidectomy (1994). In 1995, I started taking Synthroid.

I’ve been on the “healthy diet” for decades (not years): flax, seeds, african and middle eastern grains, tomato juice, coconut juice, lemon juice, green tea, celery, whole-grain, brown rice, romain, mustard, turnip green, collard green, and many other vegetables and dairy (yogurt) that I thought were good for me. I also drank coffee and ate the really, really dark chocolate. I enjoyed all of it, but I thought it was healthy for me.

Then I was dx’d with really, really low HGH, by Dr. Maher Gawhji, Endocrinologist (Memphis, TN) who is brilliant. he discovered the connection between the tumor on my pituitary gland and the low HGH.

Then, I had kidney stones. I started a low-oxalate meal plan and started taking Rx potassium citrate and eliminated the above-mentioned.

Went back to have an HGH and Thyroid Profile. Results were that my HGH levels were normal. (My previous results were so low – 50% below normal for my age – that we were desparate to get the injections.)

I also have fibromyalgia and chronic pain disease,and put on weight at an incredible rate, despite vigorous exercise and diet, and literally starving myself.

I think you may be onto something significant.

ben nguyen

Since plants/berries have both soluble and insoluble oxalates, are they both dangerous? I would think the insoluble oxalate is worse, since if water can’t dissolve it (into oxygen and carbon?), then it’s more likely to reach and disrupt the cells.

Not mentioned, but wouldn’t the process of cooking lower the oxalate count considerably (soluble or insoluble)?

Also, since the anarobic phylum bacteria, Oxalobacter formigenes, only lives in the large intestine, couldn’t the oxalates get absorbed in the small intestine before ever getting to the body’s natural defense?

It sounds like prebiotics might help increase the bacteria’s number in your gut, but it’s probably a good idea to take calcium supplement, and a low fat diet ( low fat since it frees the oxalate-binding calcium that would normally bind to fat)


From looking at the food lists that shows steamed vegetables are higher in oxalate than boiled vegetables, I’m assuming the oxalates only leave if they’re cooked out into a solution, like vegetables losing more nutrients when boiled because they’re lost in the water.

I think it’s better to go low-oxalate than low-fat. Fat provides too much energy to remove it from the diet. Then you’d have to start consuming starches for energy.

I’ll see if I can get answers to your other questions.


Here’s an answer I received from a member of Yahoo’s low oxalate group:

My understanding is that the soluble oxalate is worse. The theory is that it is more easily absorbed by the body – and more easily separated from the food! However, both kinds of oxalate can cause problems, because even the “insoluble” can be absorbed.

All plants will have some level of oxalate – which means that you cannot totally eliminate oxalate, but you can keep it below a critical threshold. This will be different for individuals, depending on their health status, the amount of oxalate that they have already absorbed, how leaky their gut is, etc., etc.

As for the bacteria question, I think the only one who could really speak to this is Susan. I don’t know if that makes a difference. However, the recommendation is to take calcium citrate about 10-15 minutes before the meal, in order to help the gut be less leaky.

ben nguyen


I think there’s a myth about avoiding calcium when consuming high amounts of oxalates, but I think you’re right… it’s extra calcium that is in order… otherwise, the calcium will come from somewhere else, and that’s not a good thing!

Regarding the bacteria angle, I don’t think any amount of probiotics will survive the journey to the large intestine. Our best hope perhaps, is that someday they find a prebiotic that promotes Oxalobacter formigenes to flourish!


Yes, you want the calcium to bind to the oxalate and prevent its absorption. It seems to me that the foods high in oxalate are naturally high in calcium, like spinach and sesame seeds.

I recently read of doctors using probiotic suppositories (from a husband to his wife) that restored gut flora and cured the wife of chronic diarrhea. Fascinating.

Patrick McGean

A fan of Joe Mercola informed us of your work about oxalates (an unknown) to our research. We study organic sulfur added back into the diet because our food has been sulfur deficient since 1954. Chemical fertilizers have broken the sulfur cycle to man.
70,000 active members, no constipation, average age of Study 77 years. 18 countries.
How can you have and oxalate without sulfur, selenium, tellurium?
Will search for your contact info but would like to to talk to someone who understands that the all of the minerals of life are necessary for life, and health.
Cellular Matrix Study
Body Human Project est. 1999


Thank you for sharing this. Considering this diet for my son. Now to find the most comprehensive/accurate food list. Anyone know of one?

Lexie | Lexie’s Kitchen


Susan’s Yahoo Group put together an extensive list. I recommend you join that group. The list is in their database.

Mark Chasteen

It seems there is alot of information which appears to quote someone elses research – and then conflicting as well. Is there not authoritative information concerning oxalate food lists ( large lists please) that exists? Combine Diets for diabetes, caridac, with a low oxalate diet and it becomes pretty difficult to make informed decisions. I would have thought as bad as high oxalates are for Nephrons – this would be a subject with real subject matter experts. Can anyone provide what has been used as authoritative guidance? Thanks in advance……getting pretty frustrated here.


I encourage you to listen to the interview, Mark. And your best bet would be to join Susan’s Yahoo group (link above). She devotes a great deal of her time answering questions there.


Thanks for your article and fabulous interview with Susan! I have been on the low oxalate diet for almost twenty years and am the author of the blog, Low Oxalate Info. I have decreased my vulvar vestibulitis pain by over 80% and completely healed my fibromyalgia, chronic fatigue, hypoglycemia (plus 11 other oxalate-related conditions) by following a moderate to low carbohydrate, low oxalate diet that emphasizes whole foods, especially meats (and their fat), veggies, and fruits.

I invite any of your readers who are interested in learning more about the low oxalate diet (and why they should join Susan’s fabulous Trying Low Oxalates Yahoo Group) to visit my blog at


I am having quite a bit of difficulty trying to develop meal plans that are both low oxalate and high alkaline. Having had calcium oxalate kidney stones, hypothyroidism and just recently a diagnosis of osteoporosis, I find it almost impossible to get most of my calcium through fruit and vegetables. Most of the good vegetables for osteoporosis are extremely high in oxalates and should be avoided altogether to prevent stone formation. Unfortunately, what food is left and the amount recommended for low oxalate is definitely not giving me the proper amount of calcium for an adult woman. I have been to numerous sites and the information is all very contradictory and confusing! I really want to avoid the bone drugs and manage with diet,exercise & sulpplements. I need help.


Ray Peat, Ph.D, recommends milk — yes milk — and eggshells, which one can dry in the oven, then grind in a grinder — they’re very high in calcium which is very bioavailable.

Lincy george

Hi Ms. Owens,

I have a 4-yr-old non-verbal autistic kid. We have done an OAT on him last year. Could you help interpret the results for us. If you need us to do a recent one, we can do that. Please do let us know. Thanks a lot!


Please contact Ms. Owens directly. She will probably not respond to this comment.


Please help with an issue I do not see addressed…
I have type 2 diabetes and adjusted my diet accordingly with very good glucose results. But I was recently told I have several kidney stones and should go on a low oxalate diet. I am actually wondering if my diabetic diet (high in grains, leafy greens, etc) may have contributed to this onset of kidney stones. But now I am stymied by what I can eat as the low oxalate foods conflict so much with diabetic menu items. I am trying to find some basic meal plans that would satisfy both of these issues without success. Do you have any advice? I am at my wits end. Thank you so much.


A diabetic diet, in my opinion, should not be high in grains. Those are pure sugar, and as a diabetic, you have an issue with sugar. I recommend you listen to my interviews under the topic of Diabetes.

I recommend you join Susan’s Yahoo group and ask that question there. They’re much better equipped to advise you on oxalates in the diet.


we found that my daughter does not metabolize oxalate foods through the OAT urine analysis. Our Homeopathologist suggest avoiding high oxalate foods. She also recommended giving my daughter 1000 mg of Vitamin C daily. I read where Vitamin C can produce Oxalate?? Should I be giving my daughter the vitamin C?


I’m sorry, I’m not a doctor nor a specialist in oxalates. I suggest you joint the Yahoo oxalate group and ask them. They can better advise you.

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