Oxalates and Food

Oxalate (oxalic acid) is a compound found in a wide range of plant foods, and it is often called an antinutrient.

While our body can typically process oxalates without any issues, they can be problematic for people with:

• Bladder pain, Interstitial cystitis
• Chronic kidney infections or kidney stones
• SIBO (small intestine bacterial overgrowth)
• Rheumatoid arthritis or joint pain
• IBS including colitis, Crohns, Celiac, and general intestinal pain
• Vulvodynia (vaginal and vulvar pain) including pain with intercourse, endometriosis

Oxalates are a toxin that plants create to protect themselves from predators. Just like a poisonous mushroom, these common plant byproducts keep animals away. Humans do not have the stomach or intestinal power or form to process these types of foods. For example, a cow has one stomach that has four distinct parts that allow it’s body to process the compounds found in plants that might otherwise harm them. 

Foods High In Oxalate

It is worth your time, effort, and health to avoid these oxalates for at least 4 weeks and see how your health is affected.

Generally, foods that contain more than 10 mg oxalate per serving are classed as ‘high oxalate’ foods.

Beverages

In addition to the above beverages, any drink made from oxalate-rich fruits or vegetables will also contain high amounts.

For example, green smoothies featuring vegetables like spinach and swiss chard can contain significant oxalate concentrations.

Additionally, plant-based “milk” made from nuts will also provide large amounts of oxalate.

Condiments

Soy products are a significant source of oxalic acid, so in addition to miso, soy-based condiments/dishes like natto, cheonggukjang, and tempeh will contain high amounts.

Furthermore, other nut butter made from almonds, pistachios, and other nuts will be high in oxalate.

Dried Fruit

As shown above, dried figs, pineapple, and prunes contain relatively high amounts of oxalate.

Furthermore, any dried versions of oxalate-rich fresh fruit (see next section) will also contain high concentrations.

Fruit

Raspberries are the most significant fruit source of oxalate.

Additionally, it is worth noting that citrus fruits contain significant concentrations of oxalic acid in their peel.

Grains, Flours, and Powders

In addition to these raw ingredients, any manufactured/pre-made foods that contain them are likely a large source of oxalate.

Here is a list of possible examples;

• Bread
• Cakes
• Chocolate bars
• Cookies
• Pancakes
• Pastries
• Pizza

Packaged Cereal Products

Here is a breakdown of the oxalate data that is available for popular cereal brands.

General Mills

Kashi

Kellogg’s

Post

Other

Nuts

Nuts contain a substantial amount of oxalate even in relatively small amounts.

Here is a look at the available data.

Walnuts (and other nuts) will also contain oxalate in varying concentrations.

Additionally, be aware of nut products such as almond flour, nut butter, and any kind of food with nut ingredients.

Vegan Proteins

Some popular vegan-friendly protein options contain oxalate due to their soy content.

However, the available data for this group is not significant, and the amounts may vary depending upon brand/specific ingredients.

Vegetables (and Beans)

Remember that only the foods that have available (and reliable) data are here.

What Is a Low-Oxalate Diet?

Low-oxalate diets are frequently characterized as being <100 mg per day (4).

However, this classification can vary, and some research suggests that individuals at risk should limit oxalate to <50 mg (5, 6).