Low Oxalate Diet – Helpful Or Harmful? – Food Pharmacy

Graeme Jones

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Low Oxalate Diet – Helpful Or Harmful?

Low oxalate diets are one of the newer kids on the block when it comes to elimination diets.  Elimination diets are used by practitioners to manage symptoms in people with digestive disorders such as IBS. Sometimes at Nordic Clinic we will use a low oxalate diet, but it depends on the evidence, patient risk, history and symptoms.   

Oxalate is a compound found in foods such as beans, leafy greens, and nuts that seemingly causes reactions in some. Additionally, humans make oxalate in the liver and unfortunately, we lack the ability to break oxalate down. 

The primary risk of high oxalate in the body is the formation of calcium oxalate stones, the most common form of kidney stone. However, oxalate may cause problems elsewhere. Where the minefield starts for us at Nordic Clinic is it’s hard to determine if oxalate problems are driven by increased production, increased absorption, or poor removal, and possibly a combination of them all. 

Though a low oxalate diet is used regularly to manage symptoms in people with gut or kidney problems, there are pros and cons to its use. Grab some nuts, or not, and read on.

Pros of a Low Oxalate Diet

There is little doubt that dietary oxalate can be a problem for those with a compromised intestinal tract. Normally, the small intestine and first part of the colon secrete oxalate. This means that rather than absorbing it into the blood, cells of the gut spit it back into the gut. Towards the end of the colon, the large intestine, oxalate is more easily absorbed into the blood. (1)

When having problems with oxalate, reducing dietary intake can help manage symptoms. In addition to being effective, it’s easier to manage oxalate intake than production. Furthermore, if you are absorbing too much oxalate, cutting back intake can prevent the formation of stones in the kidney and other organs – sounds like a good deal to me!

Ultimately, oxalate behaves very badly in an inflammatory environment as inflammation prevents oxalate secretion and promotes stone formation (2). Reducing intake during periods of high systemic inflammation can prevent the formation of calcium oxalate stones in the kidney and other organs. In addition, since gut inflammation increases absorption, reducing dietary intake prevents increased absorption.

Seems there are some serious pros to a low oxalate diet. Now let’s look at the flip side.

Cons of a Low Oxalate Diet

Though useful for managing symptoms related to high oxalate in the body, there are some negatives to relying on a low oxalate diet. First, if oxalate is high because you’re producing too much, cutting back on dietary intake may manage symptoms but does not address the cause. One major cause of increased oxalate production is type 2 diabetes, so blood sugar dysregulation should be addressed.

Second, while we don’t produce enzymes that break down oxalate, members of our microbiome do. Oxalobacter formigenes is a well-known member of our microbiome that both breaks down oxalate (3) and causes our colon to secrete more of it back into the lumen for removal (4). The presence of O. formigenes is primarily dictated by oxalate intake, so a low oxalate diet may reduce our ability to handle oxalate. This may make matters worse and explain why some patients, when going on an elimination diet although getting better in the short term, develop worse reactions over time and have even less tolerance for oxalates. Eating out becomes a nightmare. 

Thirdly, as with all restriction diets, a low oxalate diet can lead to nutritional deficiencies. Greens, beans, and nuts are nutritious foods generally associated with better health and longevity. Though you can replace some of these nutrients, there may be other as-yet-discovered nutrients in these foods that provide significant benefit. 

Finally, there may be other digestive imbalances at play that need resolving such as SIBO, dysbiosis, parasite, bacterial or fungal infections, which may be impacting oxalate removal indirectly. There are patients that come to the clinic thinking they have oxalate issues, which they do not –  once we improve the digestive environment some can go back to eating oxalates.

A Low Oxalate Diet Can Improve Symptoms but Doesn’t Address the Root Cause 

Low oxalate diet – helpful or harmful? A low oxalate diet can be useful for managing symptoms and reducing inflammation in people with digestive disorders. If reducing dietary oxalate improves your symptoms, it’s important to investigate further to find the cause. Furthermore, if you have type 2 diabetes, a low oxalate diet is a good idea until you get your blood glucose under control.

If there is inflammation in the gut, using a low oxalate diet while reducing inflammation can help improve your tolerance. However, it’s crucial to identify what’s causing the sensitivity rather than just implementing a low oxalate diet long-term. The reliance on a low oxalate diet long-term may cause you more serious problems including nutritional deficiencies and a reduced tolerance for dietary oxalate, so weigh up the pros and cons carefully before embracing it. 


1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2430047/
2. https://www.kidney-international.org/article/S0085-2538(17)30827-X/pdf
3. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3071521/
4. https://jasn.asnjournals.org/content/28/3/876



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