Though the ingestion of plants may have many health benefits, for some people, their ingestion does have drawbacks, oxalates being one. Different plants contain types of prebiotic fiber, terpenes, and polyphenols that can benefit our health. Plants also contain some compounds that cause health issues, including histamine, salicylates, and oxalates. Oxalate ingestion for some people that cannot eliminate them properly can cause serious health issues, including joint pain, muscle pain, vaginal pain, kidney stones, cardiovascular inflammation, and cognitive dysfunction. What are oxalates, what foods contain oxalates, and what can one do to improve their oxalate elimination processes?

What are Oxalates?

Oxalates (salts of oxalic acid) are naturally occurring compounds that both our body produces and are in many of the foods we consume daily. Daily adult oxalate intake is usually 80-120 mg/d; it can range from 44-1000 mg/d in individuals who eat a typical Western diet. Our body produces oxalic acid through the metabolism of vitamin C (cadmium can accelerate this metabolism, so people with cadmium toxicity may have side effects from vitamin C supplementation because of the production of oxalate acid from vitamin C) and during the Krebs cycle when oxaloacetate is hydrolyzed to oxalate and acetic acid by the enzyme oxaloacetase within our mitochondria. In addition, oxalic acid is formed from ingesting ethylene glycol. Ethylene glycol is metabolized into glycolic acid, then into glyoxylic acid, and finally to oxalic acid. Our kidneys metabolize oxalates and express them into our urine to be eliminated from our body. Oxalates are formed in plants as a defense mechanism to keep other animals, fungi, and insects from consuming the plant. Plants also form oxalates to protect themselves from metal soil toxicity (phytoremediation) by binding some metals, including lead, cadmium, and aluminum. Finally, some fungi/yeast, including Aspergillus, Penicillium, and possibly Candida, can produce oxalic acid.1 2 3 4 5 6 7

Oxalate Level Food and Herb List

Join the Trying Low Oxalate Group on Facebook and request oxalate spreadsheet access from the moderator for the most updated information. For example, some brands of tea may contain lower amounts of oxalates listed on the spreadsheet, the following list is a general list.8 9

Juicing increases oxlate concentration of food. Boiling and discarding the water afterward reduces the oxalate concentration of food. Most extracts or oils of elevated oxalate foods are low oxalate unless listed.

Amaranth – high

Animal liver – medium (including animal liver supplements)

Apple – low (best to remove peel, juice is also low)

Apricots – very low

Artichoke – medium

Arrowroot – medium to high

Asparagus – medium

Avocado – medium to high (very ripe Hass avocados might be low)

Banana – medium (1/2 ripe), high (one whole ripe)

Beans – high (garbanzo beans (chickpeas), lima beans, and mung beans are low)

Bean sprouts – medium

Beer – high

Beets – high

Beet greens – high

Blackberries – high

Black pepper – high (1/8th of a teaspoon once daily might be ok)

Blueberries – low to medium (some people do better with less than a half a cup of wild organic frozen blueberries)

Broccoli – low (boiled) to medium

Brussel sprouts – low

Buckwheat – high

Butternut squash – medium

Cantaloupe – low to medium

Carob – high to very high

Carrot – medium to high

Cassava – medium to very high

Cardamom – medium (one ground teaspoon)

Caraway seeds – high

Celery – medium (half cup) to high

Chia seeds – very high

Chicory – medium

Chocolate – very high

Cinnamon – very high

Collagen (bone broth, collagen protein, gelatin)  – possibly high, the amino acid hydroxyproline is metabolized into glycolic acid and then into oxalic acid. Some people with oxalate issues can tolerate collagen ingestion in moderation.

Collard greens – low (boiled) to medium

Corn – medium (one corn masa tortilla low, corn starch is also low)

Currents – high

Dandelion greens – high

Dates – medium (1/2 cup)

Dewberries – high

Edamame – high

Elderberry – high (extract supplements are low)

Eggplant – high

Endive – low

Escarole – high

Figs – high

Flaxseed – medium

Fresh fennel – medium

Ginger – low (teaspoon of grated fresh ginger), very high (ground ginger)

Gooseberry – high

Grapefruit – medium

Grapes – low to medium

Green Beans – high

Jerusalem artichoke (sunchoke) – very high

Kale – medium (one cup)

Kiwi – medium (Golden 1/2 cup), high

Kombucha – medium to high

Leek – medium

Marshmallow root – high

Milk thistle – high (silymarin extract is very low if any)

Millet – high

Nut butter – high

Nuts – high

Oats – high

Okra – high

Olives – high

Onions – low (white, yellow), medium (red)

Oranges – varies (one cup of Simply Orange juice no pulp or one fruit), high (peel)

Quinoa – high

Papaya – low to medium

Parsley – high

Parsnip – medium (1/2 cup)

Pear – low (Bartlett one), medium

Peanuts – high

Peppers – low (ripe red), high (green/yellow)

Persimmon – medium

Pineapple – low (canned or fresh 1/2 cup, juice one cup)

Plantain – high

Plum – low to medium (one red plum or one cup)

Pomegranate – very high

Potato – high (boiled skinless red new potatoes are low)

Poppy seeds – very high

Prune – medium (one and a half ounces of juice or pitted prunes)

Pumpkin – medium to high canned pumpkin

Raisins – low (1/4 cup) to medium (1/2 cup)

Raspberries – medium

Rhubarb – high

Rice – low (black, white, wild) medium (brown)

Rutabaga – high

Slippery elm – high

Spinach – very high

Snow peas – medium

Soy – low (San-J Organic Tamari, few teaspoons), high

Star fruit – high

Stevia – low

Strawberries – low (fresh or frozen 1/3 cup)

Sunflower seeds – medium

Sweet potato- high

Swiss chard – very high

Tamarillo – high

Tangerine – low to medium

Tapioca flour/starch – medium to high (high per half cup of flour)

Taro – high

Tea (black, green, and white) – high

Thyme – medium

Tiger nuts – medium

Tofu – high

Tomato – medium

Tumeric – high (curcumin extract is very low if any)

Wheat – high

Yam – high

Symptoms of Poor Oxalate Metabolism and Hyperoxaluria (Oxalate Burden)

Oxalates can combine with other minerals and heavy metals within our body and cause significant health issues. Oxalates that are ingested are either bonded to minerals that we ingest, including calcium, zinc, and magnesium. When the oxalates are mineral bonded in the digestive tract, they are eliminated through our stool. Oxalates that we consume can also become ingested by Bifidobacteria, Lactobacillus, and Oxalobacter formigenes occupying our digestive tract. If oxalates are not eliminated through our stool or consumed by bacteria, they are absorbed into our bloodstream. Some of the oxalates deposit themselves throughout our body. Hopefully, most that enter the bloodstream are filtered by our kidneys and eliminated in our urine. During metabolism by our kidneys, oxalates may bind with other metals and minerals to form crystals expressed in our urine. If large enough amounts of oxalates combine with the minerals calcium or iron, for example, within our kidneys, kidney stones may form. Kidney stones, if large enough, can obstruct the urinary tract and cause severe pain, bleeding, inflammation, and distress. Iron oxalate crystals can cause significant oxidative stress within the body and inflammation and diminish iron stores, leading to anemia. Finally, though oxalates bind to heavy metals, if the oxalates are not eliminated from the body, they can collect in tissues and cause further differing amounts of oxidative stress depending on the bonded heavy metal.10 11 12 13

Oxalates can also form crystals anywhere within your body, including joints, bones, blood vessels, lungs, and even the brain. Oxalate crystals that form in our joints cause joint pain and inflammation, similar to uric acid crystals in gout. Oxalate crystals that form in our blood vessels could increase the risk of blockages and cerebrovascular and cardiovascular events. Oxalate crystals that form within our bones may replace bone marrow and reduce its formation and lead to anemia and immune suppression. Oxalate crystals that deposit in our lungs may worsen conditions, including sarcoidosis, especially iron oxalate crystals. The medication condition vulvodynia might also be caused or worsens by oxalic acid formation within the vagina, which would cause painful sex. Finally, increased levels of urinary oxalate excretion have been found in autistic children.14 15 16 17 18 19 20

What May Lead to Hyperoxaluria?

21 22 23 24 25

  • A lack of Bifidobacteria, Lactobacillus, and Oxalobacter formigenes occupying your gastrointestinal microbiome.
  • Fat digestion issues, non-absorbed fatty acids can bind to calcium, interfering with its binding to oxalates.
  • Ingesting a diet heavy in oxalates while having oxalate metabolism issues.
  • Lack of dietary ingestion or supplementation of the minerals calcium, zinc, and magnesium, which have all been found to bind to oxalates.
  • Leaky gut can lead to more oxalates entering into the bloodstream from the digestive tract before they are bonded by minerals and eliminated or digested by Bifidobacteria, Lactobacillus, and Oxalobacter formigenes.
  • Inherited oxalate metabolism disorders.
  • Oxaloacetate supplementation when having oxalate metabolism issues.
  • Yeast dysbiosis
  • Vitamin B6 deficiency leads to the enzyme amino alanine glyoxylate transferase (AGT) being produced less.
  • AGT metabolizes glyoxylic acid, and when AGT metabolizes less of it, it can be metabolized into oxalic acid by the enzyme lactic acid dehydrogenase.
  • Vitamin C containing food ingestion or supplementation (Intravenous vitamin C as well) when you are cadimum toxic and/or having oxalate metabolism issues.

So, What Can Be Done If You React Negatively to Oxalates?

Great Discussion on Oxalate Metabolism Issues

If you want to increase your microbiome’s ability to metabolize oxalates then taking a probiotic like Smidge and supplementing with the prebiotic 2-FL (Holigos) may help increase colony-forming units of Bifidobacteria and Lactobacillus within your digestive tract. If you suffer from some of the symptoms above of hyperoxaluria, for example, kidney stones and/or joint pain and test low for oxalate metabolism, then ask your healthcare professional about doing the following protocol to find some relief hopefully. Finally, companies are working on marketing a supplemental strain of Oxalobacter formigenes that should hopefully be out in a few years.

If you have many of the hyperoxaluria symptoms and/or you have elevated oxalate levels in urine testing, going on a diet that is low in oxalates for a period might be crucial for your recovery. You might be able to stop the low oxalate diet once your body’s total oxalate load is lowered, treating yeast dysbiosis if you are suffering from it or if you can metabolize oxalates better.26

  • Begin slowly consuming fewer milligrams of oxalates in your diet and eventually transitioning to a low oxalate diet in a few months. You should attempt to reduce the amount of oxalates you consume by five to ten percent each week. Reducing oxalate consumption can lead to oxalate dumping as the body tries to detoxify, which can cause or worsen symptoms of hyperoxaluria. The following is a link to a good low oxalate diet.
  • Boiling high oxalate foods and draining/discarding the water can reduce the amount of oxalates in the food from as much as 75%. In people who are extremely sensitive to oxalates, this probably will not make high oxalate foods non-reactive, but medium oxalate foods might be made tolerable.27
  • Pure Encapsulations calcium/magnesium citrate – two capsules with each meal that contains oxalates.28 29 30
  • Pure Encapsulations P5P – one capsule every other day with breakfast, no longer than two weeks unless under the supervision of a healthcare professional. Long-term vitamin B6 supplementation in some people can cause toxicity (mainly neuropathy).31 32
  • Relieve yeast dysbiosis if you are suffering from it.
  • Maintain proper hydration, which can help your kidneys express oxalates into your urine. If your urine is clear and not pale yellow, you are consuming too much fluid.
  • Supplementation of N-aceytlglucosamine (do not use if you are allergic to shellfish or if you are suffering from yeast dysbiosis, it can feed the yeast) may reduce pain caused by elevated oxalates by increasing hyaluronic acid production, especially in people suffering from vulvodynia.33
  • If you are suffering from a lack of bile production or biliary sludge supplementing with artichoke extract, consuming one cup of organic black coffee in the morning daily or consuming extra virgin olive oil frequently might help.34 35 36
  • Avoid supplementation of vitamin C (for some people, they can tolerate less than four grams daily before symptoms of elevated oxalates occur, only avoid if it triggers symptoms), chitosan, and oxaloacetate.37
  3. Gundry, Steven. The Plant Paradox. Harper Wave, April 25, 2017
  7. Urry, Lisa, Cain, Michael, Wasserman, Steven, Minorsky, Peter, Reece, Jane. Campbell Biology, Pearson, October 29,2016
  25. Gundry, Steven. The Plant Paradox. Harper Wave, April 25, 2017