How Much Oxalate Is in Watercress?
mg oxalate
per serving
Serving: 1 cup (58 g)
Verdict: 🟢 Safe
Per 100g: 8 mg
Data: Harvard T.H. Chan SPH (2024)
In practical terms, Watercress is a low-risk food for kidney stone patients. Its 4 mg oxalate per serving stays under the 25 mg line, so it can appear in your regular rotation without extra calculation. As always, staying hydrated and getting dietary calcium supports stone prevention.
Among vegetables, Watercress sits well below the category average of 27 mg. For context, 219 out of 271 vegetables (80%) are rated 🟢 Safe (under 25 mg oxalate/serving). The average vegetables in our database has 27 mg oxalate per serving — which means Watercress is 86% below the category norm. Within its specific category, Watercress ranks among the lower-oxalate options. This context matters because two 'Safe' foods can have very different oxalate levels — one might have 5 mg while another has 24 mg. Both are Safe, but the first gives you more dietary flexibility. Browse all vegetables rated Safe to compare within the same verdict level.
Why does oxalate per 100g matter?
Per-100g values put every food on the same scale, which is handy when serving sizes differ a lot between foods — or when your portion doesn't match the standard serving. It lets you compare apples to apples on oxalate density. Applied to Watercress: 4 mg oxalate per 1 cup — Safe per Harvard (2024).
How accurate is the oxalate measurement?
The measurements use ion chromatography, the accepted reference method for oxalate. That means real lab values for each food rather than inferred numbers. Some natural variation exists between samples, but this is the strongest published data set. Watercress comes in at 4 mg oxalate per 1 cup (Safe) in the measured database.
How does this compare to other foods?
Foods under 25 mg per serving are rated Safe. Foods between 25-99 mg are Caution. 100+ mg is Avoid. Check the food's category page on OxalateWatch to see how it compares to similar foods. Applied to Watercress: 4 mg oxalate per 1 cup — Safe per Harvard (2024).