Oxalates and the Low Oxalate Diet: Interview with Karla Wiersma and Julie Matthews


Oxalates are sharp crystals that are very inflammatory. Oxalates bind to minerals in the diet like calcium and can create mineral deficiencies. They can perpetuate a yeast overgrowth, even if you are on a low sugar and starch-free diet like the GAPS diet. They can cause chronic pain and inflammation including in the gut. Oxalates can not only lodge in inflamed tissue causing chronic pain for years, such is the case with vulvodynia. Oxalates can also affect the cellular “works” like the mitochondria causing low energy, low thyroid, blood sugar imbalance, and I suspect mitochondrial disorders. Oxalates are high in many nutrient-rich foods such as spinach, nuts, beans, and more. This means that many well-intentioned parents inadvertently add high oxalate foods that may be problematic for some children, such as almond flour on grain-free diets like SCD and GAPS and spinach juice in an attempt to increase nutrition in a child’s diet. A recent study, “A potential pathogenic role of oxalate in autism” showed that children with autism had 2.5-3 fold increase in oxalates in urine and plasma (respectively), the first study of it’s kind. I’ve been working a lot with the low oxalate diet in my one-on-one nutrition practice, and initially I was a bit surprised by the large number of children with autism that have a problem with oxalates, and excited by the good response many of them have with the low oxalate diet and supplementation. Additionally, oxalate issues are not only an issue for children with autism, I have seen positive results with adults with certain autoimmune and pain-related conditions. Much of the information we have today about oxalates and autism comes from Susan Owens, creator of the trying_low_oxalates yahoo group, to whom we are so grateful for her work. You can donate to her Autism Oxalate Project at her website lowoxalate.info. Listen to my interview with Karla Wiersma, a mother and active member of the oxalate yahoo group, and read the transcript. The interview is full of cutting-edge information! We discuss:

Oxalate and Low Oxalate Diet Resources Family Experience with Oxalates Crystals: Biggest Indicator of High Oxalates Improvements from Low Oxalate Diet Causes/Contributors to Oxalate Issues Common Symptoms of Oxalate Issues Crystals in Urine, Sandy Stools, and Skin Rashes Yeast Flare Up, Oxalates, and Biotin GAPS/SCD Diet and High Oxalate Pitfall Soluble Oxalate vs. Insoluble Oxalate Oxalate Numbers and Super High Oxalate Foods Supplement Support for Oxalate Issues and the Low Oxalate Diet Supplements for Oxalate Dumping Fat Malabsorption and Oxalates Certain Vitamins and Minerals Taken Away from Meals


Julie Matthews is a Certified Nutrition Consultant who received her master’s degree in medical nutrition with distinction from Arizona State University. She is also a published nutrition researcher and has specialized in complex neurological conditions, particularly autism spectrum disorders and ADHD for over 20 years. Julie is the award winning author of Nourishing Hope for Autism, co-author of a study proving the efficacy of nutrition and dietary intervention for autism published in the peer-reviewed journal, Nutrients, and also the founder of BioIndividualNutrition.com. Download her free guide, 12 Nutrition Steps to Better Health, Learning, and Behavior.

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  1. I would love to hear the interview as well. I can’t find the link.

  2. I’m one of those folks on GAPS who has been dumping oxalates for about 2.5 years now, am still on Low Oxalate Diet, and I’d love to listen to this podcast. Happy to pay to listen. I’ve improved a lot eating LOD and GAPS, but am having a monthlong diarrhea dump at present, and just want to brush up on the whole issue, to see if there are stones left unturned.

    • HI Patty, Let us know if you are not able to access it.

  3. please send me the audio and transcript interview on low oxalate diet

  4. Besides Vulvodynia – women (and men) also can get lichen sclerosis due to a high oxalates diet. Doctors don’t give patients with lichen sclerosis any options except to give them steroids (which makes the problem worse). Fixing their leaky gut is the answer. This is important to mention as many people don’t understand the connection. thevpfoundation.org and lowoxalate.info are good resources to find out more information.

  5. Thanks for continuing to discuss oxalate on your wonderful blog. Can’t wait to hear the interview.

  6. I was unable to get the link to work to receive the download. I would like to know if Susan O has yet acknowledged that herbs like gold coin grass help the kidneys to dump oxalates by breaking down the calcification issues of the crystals. And whether she has acknowledged that the kids are full of worms and bacterial infections that need to be treated in order for symptoms to go down. It is tiring to read that we have to starve our kids of good nutritional foods to reduce a symptom instead of treating the cause.

    • Sounds like someone has an axe to grind. I guess that it would be a better idea if you just asked Susan yourself, and also prove how oxalates are “good nutritional foods”. They aren’t.


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