Should You Be On a Low-Oxalate Diet?

While some people know that a low-oxalate diet can help curb the risk of developing kidney stones, most people aren’t aware that these compounds can lead to or worsen other conditions in some people. Since many high-oxalate foods seem to be part of a “healthy” diet, their impact may slip past people’s radar. I’m going to discuss what exactly oxalates are and why it may be in the best interest of some people to eliminate them. Here’s what you need to know.

What are oxalates?

Oxalate (or oxalic acid) is a naturally-occurring molecule found in the human body and a variety of plant-based foods. Since our bodies don’t need oxalates, they combine with other waste materials that are excreted through the urine and stool.

Can oxalates cause problems?

Most people can expel about 90 percent of the oxalates in their body with no problem. If you’re consuming an excessive amount of oxalates or have pre-existing health conditions, however, your body can struggle to get rid of them. As oxalates build up, they can bind to calcium, blocking the absorption of calcium and forming crystals. In some people, these crystals continue to build until they form calcium oxalate kidney stones, the most common type of kidney stone.

Oxalate build-up can also interfere with nutrient absorption. As mentioned, oxalates tend to attach to minerals in the gut, which prevents the minerals from being absorbed. For example, spinach, which has a high amount of calcium and oxalate, can stop calcium from being absorbed. One study showed that fiber and oxalates have a similar interaction, leading to drops in levels of zinc, magnesium, and calcium after one week on a high-oxalate diet.

Who should follow a low-oxalate diet?

People with specific conditions may benefit from a low-oxalate diet:

• Those with kidney stones: Calcium oxalate stones, the most common type of kidney stones, are caused by too much oxalate in the body. People who have had at least one kidney stone are advised to lower oxalate consumption.
• Antibiotic users: O. formigenes is a type of bacteria in the gut that feeds off oxalates and significantly reduces their build-up. While antibiotics are sometimes necessary, they can wipe out this strain of bacteria in the gut. Those with a long history of antibiotic use may need to reduce oxalates as their microbiome rebalances.
• Those with leaky gut: As mentioned earlier, a build-up of oxalates can interfere with nutrient absorption. Leaky gut, a condition that also affects the gut’s ability to absorb nutrients, can compound this effect.
• Children with or at risk for autism spectrum disorder (ASD): Science has found a potential link between oxalates and the development of ASD. Studies have shown that children with autism may display impaired kidney function, making it more difficult to process oxalates.
• Those with hyperoxaluria or hypercalciuria: These rare conditions result in chronic kidney and bladder stones caused by an overproduction of heightened absorption of oxalates.
• Potentially those with autoimmune disorders: Oxalates in the diet can reduce mineral absorption and use up valuable bodily detoxification resources. This may contribute to gut dysbiosis—a potential contributing factor of autoimmune and inflammatory diseases.
• Other conditions: These conditions may also have a link to oxalates in the diet: urinary tract infections, vulvodynia, yeast overgrowth, fibromyalgia, pain, neurological symptoms and more.

Which foods are high in oxalates?

So, what does a low-oxalate diet look like? Here are some common foods with high levels of oxalates that you should avoid if on a low-oxalate diet: