oxalates in strawberries

Oxalates: A Silent Gut Health Killer?

Some people will do everything they can to improve their gut health, including adapting a sensible diet. They’re doing nothing health experts would deem as wrong. Yet, these people still experience severe gastrointestinal distress. That’s because even healthy foods can have an adverse impact on the body, such as foods rich in oxalates. Oxalates are anti-nutrients found in nutrient-dense plant-based foods. Let’s take a closer look at this paradox and how it may impact your gut health.


What Are Oxalates?

oxalates bleach straw hats
“Oxalate” is a term to describe the chemical reaction between oxalic acid and other substances in our system. Oxalic acid is highly acidic and is used as natural bleach for clothing materials, such as straw hats [1].
Our bodies produce oxalic acid on its own. We also convert Vitamin C into this molecule when we metabolize the antioxidant [2]. This transition happens when oxalates come into contact with cadmium found in zinc, lead and copper.
Typically, oxalates bind to other minerals, which then show it out the system. However, we re-introduce oxalates back into the fold by consuming foods with them. That’s where oxalates become a problem.


Why Are Oxalates Bad?

Remember when we said oxalates attached to trace minerals that showed them the door? That may seem like an easy fix to us. However, it’s a bit of a problem for our body.
When oxalates bind to these nutrients, it renders them useless. So, our cells don’t get the much needed nutrition they deserve. That’s why oxalates are called anti-nutrients.


Which Nutrients Do Oxalates Bind To?

Oxalates are known to be overly discriminatory. They can attach themselves to many trace minerals. However, oxalates have a bigger affinity for some of the most crucial nutrients.



Magnesium is a catalyst for over 300 functions throughout the system [3]. Many of these tasks involve our gut health. This essential mineral influences our stomach muscles. Therefore, magnesium is essential for the digestion of food.
In addition, magnesium helps bring balance to our acidic gut biome. That way, more nutrients have a greater chance of surviving and becoming absorbed by the body. Without magnesium, the harsh environment may start to damage the gut lining, resulting in Leaky Gut Syndrome.
Lastly, magnesium also helps push stool through the small intestines. Therefore, a magnesium deficiency can lead to constipation and sharp abdominal pains [4].




Oxalates also have an affinity for iron. Iron is used to create hemoglobin. This protein allows blood cells to carry oxygen throughout the system. Without iron, we won’t have the energy necessary to heal wounds, promote digestion, or fight off harmful stomach bacteria.
Speaking of which, iron interacts with our intestinal flora. Many depend on this mineral for their own growth, although a slight few have shown independence.
One analysis on the gut biome and iron connection found,

“Iron is critical for the replication and survival of almost all bacteria, with a few exceptions, which acquired alternative metabolic solutions from evolution. Lactobacillus plantarum was the first identified iron-independent microbial strain, which contains just one or two iron atoms—a level that is considered to be too low to provide iron with any conceivable biological function…On the other hand, some gut strains like Bacteroides fragilis are strongly dependent on heme [5].”

Pharmaceuticals (Basel)
Therefore, iron influences both beneficial and harmful stomach bacteria. Seeing as the majority of iron absorbed by the body happens in the duodenum of the small intestine (about 15%), it’s crucial you have probiotic bacteria in your system.



Calcium is the other major mineral that oxalic acid has a penchant for. In fact, it’s probably the molecule’s favorite. Of the three, calcium is the least influential on our gut health. However, it plays a monumental role in our overall wellness.
calcium oxalates
This mineral is essential for bone strength. Without enough calcium, we run the risk losing bone density, developing osteoporosis, and weakening our teeth.
Calcium is the most significant eliminator of oxalates. When they bind together, calcium oxalate becomes a waste product. If we don’t have enough calcium left to usher the oxalates out, they end up in our kidneys. While there are many types of kidney stones, the majority are comprised of calcium oxalate [6].


How Oxalates Harm Gut Health

Our body is an intricate design. Every piece has a purpose. When you start removing Jenga pieces, eventually the structure will fall apart. That’s the long-term damage of too many oxalates.
oxalates are like a game of jenga
When something is amiss in our system, our receptors are onto it. They signal for our immune cells to jump into action. The first thing our immune system cells do is start inflammation.
Inflammation is meant to be a quick fix to an attack. Receptors let the system know a virus, fungi, or unwanted intestinal flora is here. Immune cells spark inflammation. Bada-bing, bada-boom! The bad guys are gone and the inflammation ceases.
Unfortunately, when we keep consuming foods that are upsetting the system, it keeps the inflammation going. Chronic inflammation is the precursor for so many illnesses, including autoimmune disorders, Irritable Bowel Syndrome (IBS), and Crohn’s Disease.


Which Foods Have Oxalates?

Everyone’s system is different. Some of us can tolerate a high level of oxalates. Whereas, others can only handle a small serving. So, the best to do is eliminate all oxalates from your diet and then slowly introduce them. Once painful GI symptoms pop up, you have met your threshold.
Here are some foods rich in oxalates:
oxalates in healthy food
• Almonds
• Beans
• Beer
• Beets
• Black Tea
• Chocolate
• Coffee
• Nuts
• Okra
• Orange
• Raspberries
• Rhubarb
• Spinach
• Stevia
• Strawberries
• Sweet Potatoes
• Wheat Bran
If you are starting to have trouble digesting oxalates, eat the food with calcium. Add cheese to your spinach salad. Put raspberries in your yogurt.


Gut Bacteria and Oxalates

The biggest reason we have trouble metabolizing oxalates is that we are lacking the enzymes necessary. However, some stomach bacteria may help us out where we are lacking. Research shows that the aptly named Oxalobacter formigene picks up a lot of the slack.
A study on probiotics and oxalates found,

“Results suggest that colonization with O. formigenes is associated with a 70% reduction in the risk for being a recurrent calcium oxalate stone former [7].”

J Am Soc Nephrol
While studies are in their infancy, other probiotics are showing promise in controlling an abundance of oxalates. Research indicates strains of Lactobacillus and Bifidobacterium might be useful in providing relief [8].
Also, pathogenic bacteria won’t help you absorb the nutrients that the oxalates don’t suck from you. So, it’s important to get your gut tested to see which stomach bacteria you do have. That way, we can formulate a custom probiotic that will help you improve your gut health.


Click Here To View Resources



[1] Brown, O. H. “OXALIC ACID POISONING.” Journal of the American Medical Association, American Medical Association, 27 Apr. 1912, jamanetwork.com/journals/jama/article-abstract/451972.
[2] Traxer, Olivier, et al. “Effect of Ascorbic Acid Consumption on Urinary Stone Risk Factors.” The Journal of Urology, U.S. National Library of Medicine, Aug. 2003, www.ncbi.nlm.nih.gov/pubmed/12853784.
[3] “Office of Dietary Supplements – Magnesium.” NIH Office of Dietary Supplements, U.S. Department of Health and Human Services, 11 Oct. 2019, ods.od.nih.gov/factsheets/Magnesium-HealthProfessional/.
[4] Siegel, J. D., & Di Palma, J. A. (2005). Medical treatment of constipation. Clinics in colon and rectal surgery, 18(2), 76–80. https://doi.org/10.1055/s-2005-870887
[5] Yilmaz, B., & Li, H. (2018). Gut Microbiota and Iron: The Crucial Actors in Health and Disease. Pharmaceuticals (Basel, Switzerland), 11(4), 98. https://doi.org/10.3390/ph11040098
[6] Alelign, T., & Petros, B. (2018). Kidney Stone Disease: An Update on Current Concepts. Advances in urology, 2018, 3068365. https://doi.org/10.1155/2018/3068365
[7] Kaufman DW, Kelly JP, Curhan GC, Anderson TE, Dretler SP, Preminger GM, Cave DR. Oxalobacter formigenes may reduce the risk of calcium oxalate kidney stones. J Am Soc Nephrol. 2008 Jun;19(6):1197-203. doi: 10.1681/ASN.2007101058. Epub 2008 Mar 5. PMID: 18322162; PMCID: PMC2396938.
[8] Abratt, Valerie R, and Sharon J Reid. “Oxalate-Degrading Bacteria of the Human Gut as Probiotics in the Management of Kidney Stone Disease.” Advances in Applied Microbiology, U.S. National Library of Medicine, 2010, www.ncbi.nlm.nih.gov/pubmed/20602988.

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