Do spinach and kale make up the crux of your diet? Or does your diet consist mostly of nuts, seeds, and beets? Even though these are great foods, you might not be getting all the nutrients that you think you are. Why? Something called oxalates.
Oxalates are organic acids produced by plants—they use these acids to protect themselves from insects. Oxalates might also be a byproduct of fungi such as candida and aspergillus. Normal metabolic processes also contribute as well as our dietary consumption.
If our body can’t process oxalates, they can crystallize and act like shards of glass, creating irritation wherever they go. Oxalates can form crystals in the heart, bone, brain, and kidney, and when we excrete them from the kidneys, they damage our genitalia, leading to vulvar pain in women.
Conditions such as fibromyalgia, kidney stones, anxiety, leaky gut, and autism might actually have oxalates at their root. Even thyroid issues may have an oxalate basis. Dr. Izabella Wentz, RhP and author of Hashimoto’s Thyroiditis: Lifestyle Interventions for Finding and Treating the Root Cause, states that autopsies have found that 79% of adults have oxalate crystals in their thyroid glands, which could lead to inflammation and ultimately autoimmune issues.
In addition to tissue damage, oxalates have been shown to inhibit our ability to metabolize carbs as well as impair the ability of our mitochondria to make energy
According to Andrew Rostenberg, DC, as oxalates are absorbed, they may force us to lose precious sulfates required for detoxification, growth and repair of our cells, moving blood, and detoxifying. That’s not good! But I believe the most pressing issue with oxalates is that they bind with minerals, thereby keeping us from absorbing things like zinc and calcium while simultaneously preventing the excretion of toxic metals like mercury and lead.
Symptoms of oxalate overload
- Pain in the body
- Burning with urination (interstitial cystitis)
- Burning with bowel movements
- Leaky gut
- Kidney stones
What is the root cause of oxalate overload?
Not everyone is sensitive to oxalates. The Oxalosis and Hyperoxaluria Foundation states the following causes for those who are:
- Dietary hyperoxaluria happens when you eat too many oxalate foods that can’t be eliminated by the body.
- Enteric hyperoxaluria conditions include intestinal disorders such SIBO, Crohn’s disease, short bowel syndrome, dysbiosis, etc., all of which affect absorption ability.
- Primary hyperoxaluria is “A rare, genetic disorder of liver metabolism that often results in life-threatening damage to the kidneys. In this type, the liver doesn’t create enough of a certain protein (enzyme) that prevents overproduction of oxalate, or the enzyme doesn’t work properly. Unlike dietary or enteric hyperoxaluria, the amount of oxalate in the urine is not greatly affected by changes in dietary oxalate.”
In addition, having low levels of calcium may increase oxalate levels—we need calcium to bind to oxalates in order to remove the latter from the body.
What foods contain oxalates?
Foods high in oxalates are foods that contain more than 10 mg per serving. The University of Pittsburg Medical School has a good list of oxalate-rich foods on their website, plus they classify foods by their oxalate content. Find more here:
How much oxalates is safe to eat?
Nutrient-rich foods such as greens, nuts, and fruits contain oxalates. For those sensitive, since they are such healthy foods, we do not want to eliminate them from our diet—instead, it’s best to limit their intake while also supporting our body’s ability to make use of them. A normal diet includes about 250 mg of oxalates per day. For those who are sensitive to oxalates, we may choose to limit their intake to 50 to 100 mg daily. Again, we are NOT eliminating oxalates—we are reducing our intake of them.
What is an oxalate dump?
If you completely stop eating oxalates or remove them too quickly from your diet, you may experience “oxalate dumping” as your body tries to get rid of them all at once. This may result in the same symptoms you experience if you have low calcium or magnesium levels, such as muscle aches, cramps, headaches, detox issues, etc. To minimize this response, you should slowly start to reduce your intake of oxalates to about 100 mg per day. After your body adjusts to your new level, you can try to reduce your intake even further if needed.
What else can we do to minimize the effects of oxalates?
Again, if you have a known issue, then when a higher-oxalate food is consumed, it should be put on a rotated schedule of eating to prevent an over concentration of oxalates (which could lead to possibly developing a sensitivity to that particular food) and minimization of oxalate related issues.
It is also key is to drink lots of water and replace the loss of minerals and B vitamins that an over concentration of oxalates can cause.
We need to make sure that the gut is not “leaky” and that we can effectively process fats. If we can’t, fatty acids can join with calcium and oxalates destined to leave the body, thus not allowing them to be eliminated. Bile salts (ox bile) may help as well as phosphatidylcholine, taurine, and a good digestive enzyme.
Calcium can block the absorption of oxalates, so folks with a low dietary intake of calcium are more likely to be oxalate-sensitive. If you choose to eat high amounts of oxalates in a meal, consider taking calcium citrate or magnesium citrate with the meal to help excrete them. For those limiting oxalates, I really like this site: http://lowoxalateinfo.com/four-effective-approaches-to-the-low-oxalate-diet/. It’s helpful when you’re trying to manage a lower oxalate intake
B6 deficiency has been associated with oxalate issues. Why B6? B6 is a required cofactor for the enzymes that break down oxalates. The Linus Pauling Nutrition Institute reported that “A group of more than 85,000 women without a prior history of kidney stones were followed over 14 years, and those who consumed 40 mg or more of vitamin B6 daily had only two-thirds the risk of developing kidney stones compared with those who consumed 3 mg or less.” Care should be taken with supplementation, however, since daily amounts over 100 mg have been shown to possibly lead to pain and burning in the extremities.
High intake of vitamin C and iron can increase oxalate conversion, so we need to limit vitamin C supplementation. A study posted in the Reviews of Urology shows that “…these articles clearly demonstrate that 1 to 2 grams of ascorbic acid administered daily to both normal subjects and calcium oxalate stone-formers result in no urinary pH changes but in increased oxalate excretion.” Still others (such as Sterling Hill from MTHFRsupport.com) believe that vitamin C should not be in the form of ascorbic acid and should be from natural sources to minimize oxalate absorption and even then, should be limited to 400 mg per day. Basically, the jury is still out on how much is the right amount of Vitamin C for those with oxalate issues.
You may also consider reducing your sodium intake to 2 to 3 mg per day. Why? When we consume too much sodium, the kidneys begin to excrete excess calcium from the urine.
Excess protein can lead to high levels of uric acid, so don’t overdo protein consumption, either—too much protein may cause stones to form. Another downside of excess animal protein consumption is that it lowers the levels of citrate in the blood, and citrate is necessary to block stone formation.
Finally, chronic gut conditions such as Crohn’s or ulcerative colitis may contribute to malabsorption and increased oxalate absorption.
How can you test for oxalates?
There are blood tests you can run through Labcorp, but the most common test is the Great Plains organic acids test (OAT) where they test directly for oxalic, glyceric, and glycolic acids. In addition, OAT includes testing for byproducts of yeast (since yeast overgrowth goes hand-in-hand with high oxalate issues) as well as your B6 status.
Please note: Some folks may have low protein intake or issues with breaking down proteins, which may in turn lead to having low lysine levels. This has a negative impact on B6 levels since lysine is required to move B6 around the body.