What are oxalates? A guide to high-oxalate foods and who should avoid them

From spinach and nuts to tea and chocolate, a practical look at high-oxalate foods, kidney health concerns, and simple diet strategies to lower oxalate levels

Spinach is among the foods naturally high in oxalates

Updated on:

23 Sep 2026, 3:00 pm

2 min read

Naturally occurring compounds in plants are known as oxalates, also known as oxalic acid. Although they are rich in nutrients, oxalates bind to calcium as they leave your body. This can increase the risk of kidney stones in some people.

What Are Oxalates and How Do They Affect the Body?

Nuts and seeds can contain significant amounts of oxalates

Your doctor may recommend you follow a low-oxalate diet if you’re prone to kidney stones or have kidney disease. But for most people, the benefits of nutrient-dense, high-oxalate foods outweigh their risks.

Oxalates are found in healthy foods like vegetables, fruits, nuts, and grains. A low-oxalate diet means eating less than 100 mg of oxalate per day by avoiding or limiting high-oxalate foods like spinach, nuts, chocolate, and beets while eating enough calcium with meals to block oxalate absorption.

Who Should Follow a Low-Oxalate Diet?

A low-oxalate diet may be recommended for:

* People with high urinary oxalate (hyperoxaluria)

* Individuals with a history of calcium oxalate kidney stones

* People with enteric hyperoxaluria associated with Crohn’s disease, inflammatory bowel disease (IBD), short bowel syndrome, chronic pancreatitis, or bariatric surgery

* Individuals with consistently elevated urinary oxalate on 24-hour urine testing

To determine whether elevated urinary oxalate may be contributing to kidney stone risk, a 24-hour urine test is often the best way.

Individualised dietary recommendations are given to people living with primary hyperoxaluria (PH). However, dietary changes alone do not address the underlying cause of the disease because PH is a genetic condition that causes the liver to produce excess oxalate.

High-Oxalate Foods to Limit or Avoid

Spinach, rhubarb, beet greens, almonds and peanuts, cocoa and dark chocolate, black tea, wheat bran, soy products, potatoes, and green peas, to list a few.

How to Avoid High Oxalate Levels

There are things you can do to help lower your high oxalate levels and lessen the problems they can cause:

* To help ensure good health, balance high-oxalate foods with other fruits and vegetables.

* To help your body flush out excess oxalates, drink enough water.

* Get the recommended amount of calcium.

* Limit sodium and sugar intake, as it may lead to kidney stones at high levels.

* Get the recommended amount of vitamin C. Too much can increase oxalic acid production in your body.

* Cook high-oxalate vegetables to lower their oxalate content.

—manuvipin@newindianexpress.com

@ManuVipin

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