Arugula is low in oxalates. One cup of raw arugula contains roughly 20 mg of oxalate, placing it firmly in the low-oxalate category. If you’ve been avoiding leafy greens because of kidney stone concerns, arugula is one of the safest options available.
How Arugula Compares to Other Greens
Not all leafy greens are created equal when it comes to oxalates. The differences are dramatic. One cup of raw spinach contains 656 mg of oxalate, making it one of the highest-oxalate foods you can eat. Cooked spinach is even more concentrated: a half-cup serving packs 755 mg because the leaves shrink down significantly during cooking.
Arugula’s 20 mg per cup is a fraction of that. To put it in perspective, you’d need to eat more than 30 cups of raw arugula to match the oxalate in a single cup of raw spinach. Kale is even lower at just 2 mg per chopped cup, making it and arugula the go-to greens for people watching their oxalate intake.
What “Low Oxalate” Actually Means
The Oxalosis and Hyperoxaluria Foundation, a leading resource for oxalate-related conditions, breaks foods into four tiers based on oxalate per serving:
- Very high: 300 mg or more per serving
- High: 100 to 299 mg per serving
- Moderate: 25 to 99 mg per serving
- Low: less than 25 mg per serving
Arugula falls into the low category. For people following a low-oxalate diet, the general target is to keep total daily intake around 100 mg or less. A generous salad with two or three cups of arugula would use up roughly 40 to 60 mg of that budget, leaving plenty of room for other foods throughout the day.
Why Oxalate Levels Matter
Oxalates are naturally occurring compounds found in many plants. On their own, they’re harmless for most people. The concern arises when oxalates bind with calcium in the kidneys and form calcium oxalate crystals, the most common type of kidney stone. If you’ve had a calcium oxalate stone before, or if you have a condition that causes your body to absorb more oxalate than usual, keeping dietary oxalate low can reduce your risk of forming new stones.
For people without a history of kidney stones, oxalate intake from normal eating is rarely a concern. The body handles moderate amounts without issue, and calcium-rich foods eaten at the same meal actually bind oxalate in the gut before it reaches the kidneys.
Does Cooking Arugula Lower Oxalate Further?
Cooking does reduce oxalate content in vegetables, though it matters less with a food that’s already low. Boiling is the most effective method, reducing soluble oxalate by 30 to 87% depending on the vegetable. The oxalate dissolves into the cooking water, so discarding that water is key. Steaming is less effective, cutting soluble oxalate by 5 to 53%.
Since arugula starts at just 20 mg per cup, even a modest reduction from a quick sauté or wilting into a hot dish brings the number down to a negligible level. Most people eat arugula raw in salads, though, and at these levels that’s perfectly fine for a low-oxalate diet.
Best Low-Oxalate Greens
If you’re building a rotation of kidney-friendly greens, arugula and kale are your strongest options. Romaine lettuce, iceberg lettuce, and bok choy also tend to be low in oxalates. The greens to limit or avoid are spinach, Swiss chard, and beet greens, all of which rank among the highest-oxalate foods in any category.
A practical approach is to use arugula or kale as your base green for salads and cooked dishes, reserving spinach for occasional use rather than daily consumption. This simple swap can cut hundreds of milligrams of oxalate from your weekly intake without sacrificing the vitamins, minerals, and fiber that make leafy greens so valuable.