Oxalates in Foods: What You Need to Know

If you’ve ever heard someone mention oxalates and thought, “Wait, what are those?” you’re not alone. As a dietitian, I get this question a lot, especially from clients dealing with kidney stones or certain gut issues. So let’s break it down: what they are, why they matter, and who actually needs to pay attention to them.

What Are Oxalates?

Oxalates (or oxalic acid) are natural compounds found in many plant foods. Your body also produces small amounts as part of normal metabolism. Typically, oxalates leave the body through urine without causing issues. But in some situations, elevated levels can contribute to kidney stone formation, particularly calcium oxalate stones, which are the most common type.

Who Should Limit Oxalates?

For most healthy people, these compounds aren’t a major concern. But some groups may benefit from monitoring their intake:

• People prone to kidney stones: If you’ve experienced calcium oxalate stones, your healthcare provider may suggest limiting certain foods.
• People with certain gut issues: Conditions like inflammatory bowel disease (IBD) or short bowel syndrome can increase absorption, raising stone risk.
• Rare metabolic disorders: Some genetic conditions affect how the body handles these compounds.

Foods High in Oxalates

Here are some foods particularly rich in oxalates:

• Spinach
• Rhubarb
• Beets
• Swiss chard
• Almonds and other nuts
• Dark chocolate
• Sweet potatoes
• Soy products
• Buckwheat

Should You Avoid These Foods?

Not necessarily. Many foods high in oxalates are packed with nutrients. The key is moderation and balance, especially for those at risk for kidney stones. A few practical strategies include:

• Pairing high-oxalate foods with calcium-rich foods. Calcium binds with oxalates in the gut, reducing absorption.
• Staying well-hydrated to help flush them from your system.
• Consulting with a dietitian for personalized advice if you need to manage intake carefully.

Oxalates are a normal part of many healthy plant foods. For most people, they’re not something to stress over. But if you have a history of kidney stones or certain medical conditions, being aware of oxalate-rich foods and making a few smart dietary adjustments can help.

As always, talk to your healthcare provider or dietitian before making significant changes to your diet.