The Dangers of Oxalates and the Green Smoothie Health Fad

What are Oxalates?

Scanning electron micrograph of the surface of a kidney stone showing tetragonal crystals of weddellite (calcium oxalate dihydrate).

Scanning electron micrograph of the surface of a kidney stone showing tetragonal crystals of weddellite (calcium oxalate dihydrate).

Oxalates are crystalline molecules that we absorb from our diet (high oxalate foods) or are produced by an infection, like yeast/fungal overgrowth.  These oxalates can accumulate in the body and cause inflammation.  The symptoms of oxalate accumulation include pain, nephrolithiasis, and neurological symptoms and oxalates have been associated with vulvodynia (vulvar pain) and fibromyalgia pain. Oxalates are largely known to cause/create kidney stones.  Children with autism who exhibit eye-poking behavior have also been shown to have a buildup of oxalates behind their eyes, causing tremendous pain, and thus the eye-poking.  This oxalate buildup is thought to be caused by or exacerbated by calcium deficiency and you can read about this in the article, RICKETS AND EYE-POKING IN AUTISM ASSOCIATED WITH CALCIUM DEFICIENCY.  

Figure 1 - Oxalate Pathway

Figure 1 - Oxalate Pathway

Oxalate buildup can be caused by three different sources, the most common of which is diet.  Diets that contain large amounts of oxalates can cause oxalate buildup and some of the foods highest in oxalate are spinach, soy, nuts, and berries.  The second source for oxalate buildup is Candida infection or the excess of other yeast/fungal organisms, which can convert sugars into oxalates.  The third cause of oxalate buildup is genetic polymorphisms (mutations), which will be reviewed in greater detail below.  The process by which oxalate can enter and buildup in the body is shown in Figure 1.  

Green smoothies are good for you, right?  Think again. 

Spinach has been shown to have the highest oxalate content of any food, so anyone genetically predisposed to have problems with oxalate metabolism or who has a calcium deficiency and eats spinach frequently (especially raw, and especially in green smoothies because of the large amounts of spinach that can go in them) is particularly at risk for oxalate buildup and the resulting complications.  As mentioned previously, foods high in oxalate include spinach, soy, nuts, and berries, and here is a list of foods high in oxalate.

Our Laboratory Director, Dr. William Shaw wrote an article about the dangers of oxalates and the green smoothie trend, THE GREEN SMOOTHIE HEALTH FAD: THIS ROAD TO HEALTH HELL IS PAVED WITH TOXIC OXALATE CRYSTALS, which was published in the January 2015 issue of Townsend Letter and has been incredibly popular. Click here to read the article.  He also delivered a webinar about all of this and you may view that here.  

What can you do about Oxalates?

Figure 2

Figure 2

Figure 3

Figure 3

The first step to address a possible oxalate problem is to find out if you currently have excess buildup of oxalates in your body, which we measure in our Organic Acids Test (OAT).   The OAT has three oxalate markers:  glyceric, glycolic, and oxalic acids.  Figures 2 and 3 are sample reports from the OAT showing results for these markers.  In addition, low B6 and increased yeast or fungal markers are associated with increased oxalates. 

Figure 4

Figure 4

The second step is to find out if you are genetically predisposed to have a problem with oxalate metabolism and there are three genetic conditions for this, hyperoxaluria type I, type II, and type III.  The three genes that can cause an issue with oxalate are AGT (AGXT), GRH-PR, and HOGA1.  AGT and GRH-PR are able to convert glyoxalate to their glycolate or glycine respectively.   Disruptions in either of these enzymes can cause oxalates to buildup.  Buildups or low values in glycolic acid can sometimes be used to determine if you have a SNP (mutation) in either GRH-PR or AGXT.  Our GPL-SNP1000 DNA Sequencing Profile covers four different genes involved with the production and elimination of oxalates and Figure 4 shows sample results for the AGTX gene (hyperoxaluria type I).  

If it’s determined that you may have a problem with oxalates, it’s important to follow a low-oxalate diet, drink plenty of water, and take a supplement like calcium-magnesium citrate, to be sure you have plenty of calcium to bind with oxalate and eliminate it in your urine before it becomes a problem.  Vitamin B6 has also been shown to be an effective treatment for oxalates.   

Additional Resources on Oxalates

Article by our director, Dr. William Shaw:  OXALATES CONTROL IS A MAJOR NEW FACTOR IN AUTISM THERAPY

Webinar by Dr. Kurt Woeller:  CHRONIC PAIN, FIBROMYALGIA AUTISM AND THE OXALATE CONNECTION

Recent GPL blog post about oxalates

 

Clinical References on Oxalates

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