Why Are The Low Oxalate Food Lists So Inconsistent?

by Heidi on March 15, 2012

One of the biggest frustrations newcomers to the low oxalate diet have is figuring out what they can or cannot eat.  It seems like everywhere you turn, some person, organization or doctor has posted a list of low oxalate or high oxalate foods which is totally different from some other list of low oxalate or high oxalate foods.  It’s enough to make even the most determined low oxalate dieter want to cry (or at least scream!). The most important explanation for these inconsistent low oxalate food lists is that new testing techniques for oxalate content (since the 1990’s) are much more accurate than earlier testing techniques1.

Low Oxalate Blueberries

Low oxalate blueberries are often given a bad rap on out-of-date oxalate lists.

Low oxalate food lists (even those given to patients from well-meaning doctors) can often be out-of-date and do not reflect the newer, more accurate techniques.  For example, many people on a low oxalate diet are told not to eat blueberries or strawberries.  You can’t surf the internet more than a few minutes without at least one oxalate food list or authority incorrectly telling you that berries are high oxalate (15 mg. oxalate or more per serving is usually considered high oxalate).  I unfortunately gave up blueberries for almost 12 years thinking they were harming my body.  But thanks to the dedication of many scientists (and the people who fund their research!), we now know that blueberries are low oxalate (4.0 mg. oxalate per half cup) and strawberries are medium oxalate (7.8 mg. per half cup).  Hurray!  I now eat lovely low oxalate blue berries almost every day.

The second explanation for some of the variation in the low oxalate food lists is that individual plants, even those of the same species, vary in oxalate content.  Granted, some plants are going to be high oxalate no matter how they’re grown.  There’s little hope for spinach (365 mg. oxalate per ½ cup, steamed), and don’t even think about eating rhubarb (702 mg. oxalate per half cup, stewed).  But the oxalate content of other plants, like apples, varies greatly depending on factors such as the length of the growing season, harvesting practices, plant maturity (green vs. red bell peppers), plant variety (granny smith vs. gala apples), plant part (leaf vs. root), soil chemistry, fertilization and soil moisture2.  For example, green beans are usually listed as a high oxalate food (half-runner beans have 23.8 mg. per half cup) but one bush variety of green beans, Roma beans, are a medium oxalate food (8.4 mg. per half cup, boiled).  Variety and growing conditions really do matter!  (Find Roma bean seeds for your low oxalate garden here).

Bush Green Beans

Bush green beans, like medium oxalate Roma beans, are easy to grow without poles or support. You can even grow them in a container on your porch!

Since oxalate content varies from plant to plant (and especially variety to variety), it’s important to remember that the oxalate contents reported in the food lists are approximations for the oxalate content of the foods you are actually eating.  It’s also important to remember that commercial products and brands can change recipes or can change the variety of fruit or vegetable used in their recipes at any time.  For that reason, I like to think of listed oxalate values as a snapshot of the oxalate content of a food at a particular time that is best used as a guideline, not an absolute, when making decisions about how much of some food I should consume.   For example,  Kinnikinnick Kinni Kritters animal cookies (gluten-free) were tested by the Autism Oxalate Project in 2011 and at that time had 1.3 mg. oxalate per 8 cookies (buy Kinni Kritters animal cookies here).  Glutino Pretzel Twists (gluten-free) were tested by the Autism Oxalate Project in 2011 and had 2.6 mg. per 24 pretzels (buy Glutino Pretzel Twists here). Chaokoh coconut milk was tested by the Vulvar Pain Foundation in 2010 and contained 0 mg. oxalate! (buy Chaokoh coconut milk here).  However, product formulas do change and these oxalate values may no longer be correct.  One way to be sure is to call the company and ask if the product formula has changed.  If it hasn’t changed, obtain a list of ingredients and keep it for your reference.  If you ever notice something is different, try to figure out if the new ingredient is low oxalate or not.  You can then make a better choice about that whether or not to eat that product, knowing that you no longer have exact information on the oxalate content.

One thing I like to do is compare two seemingly similar products to see if I can figure out what ingredients cause the difference in oxalate contents.  For example, Tai Kitchen coconut milk has 6.5 mg. oxalate per half cup compared to Chaokoh coconut milk with 0 mg. oxalate per half cup.  The only differences in their ingredients is that Tai Kitchen coconut milk contains guar gum, but no preservatives, while Chaokoh coconut milk contains preservatives, but no guar gum.  Otherwise, both are made from pure coconut by similar processes.  This is something to keep in mind when comparing other brands that may be available at your grocery store.  I recently stopped purchasing my store’s generic brand because its ingredient list matched the Tai Kitchen ingredient list and I prefer to use a lower oxalate coconut milk in my cooking.

How do I get an Accurate Low Oxalate Food List?

The easiest way to insure that you have access to the most up-to-date, accurate list of oxalate values currently available is to join the Trying Low Oxalates Yahoo Group.  I give you step-by-step instructions on how to join and how to find and make a copy of the list in my post, How to get an Accurate Low Oxalate Food List.

Are the Oxalate Values on This Site Accurate?

All oxalate values reported on this site were tested using the new, more accurate testing techniques or were reviewed for publication in the Low Oxalate Cookbook 2 by Dr. Michael Liebman, oxalate scientist at the University of Wyoming{buy the Low Oxalate Cookbook 2 from the Vulvar Pain Foundation here (recommended way!) or on Amazon.com here}   Most of this testing was funded by the Vulvar Pain Foundation or the Autism Oxalate Project.  Please consider contributing to their testing funds or organizations, so their important work can continue.


1.)  Libert, Bo, and Vincent R. Franceschi. 1987. “Oxalate in crop plants.” Journal Agriculture and Food Chemisty 35(6):926–938.

2.)  Rahman, M. and O. Kawamura. 2011.  Oxalate Accumulation in Forage Plants: Some Agronomic, Climatic and Genetic Aspects. Asian-Aust. Journal of Animal Science. 24(3): 439 – 448.

Photo credits:  Blueberries by Mullica and A Green Bean by Wanko.

{ 47 comments… read them below or add one }