Is Purslane Safe for Kidney Stones? (Avoid)
mg oxalate
per serving
Serving: 1 cup (40 g)
Verdict: 🔴 Avoid
Per 100g: 621 mg
Data: Harvard T.H. Chan SPH (2024)
Here's the takeaway: Purslane is a Avoid food (🔴) at 248 mg oxalate per serving — past the 100 mg line. The safest approach is choosing a lower-oxalate alternative instead. If it shows up occasionally in a meal, keep the portion minimal and boost fluids.
Putting Purslane in context: it lands well above the category average of 27 mg. In the database, 80% of vegetables (219 of 271) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical vegetables here averages 27 mg oxalate per serving, so Purslane runs 818% above that baseline. That places it on the higher end for oxalate in its category. Why this matters: the gap between two Safe foods can be wide — one may hold 5 mg oxalate while another sits at 24 mg. The lower one leaves more room in your day. See all vegetables rated Avoid for a full side-by-side.
Why does the safe threshold matter?
The 25 mg cutoff comes from clinical guidance for stone formers. Below it, a food's oxalate contribution is small enough not to move the needle for most patients. Harvard's 2024 lab data sits behind these figures — direct measurements, not estimates. Purslane comes in at 248 mg oxalate per 1 cup (Avoid) in the measured database.
Can I eat this food every day?
Daily eating is fine for Safe foods (under 25 mg/serving). For Caution or Avoid foods, spread them out and alternate with low-oxalate picks. The idea is keeping your weekly oxalate load manageable, not eliminating any single food. Purslane comes in at 248 mg oxalate per 1 cup (Avoid) in the measured database.
Where does the oxalate data come from?
Harvard T.H. Chan School of Public Health (2024) via the OHF database. These are direct laboratory measurements — the most reliable oxalate data available for food. Purslane comes in at 248 mg oxalate per 1 cup (Avoid) in the measured database.
Should I also check sodium and calcium?
Yes — oxalate alone doesn't decide stone risk. Sodium pushes more calcium into urine, and calcium from food (not supplements) helps bind oxalate during digestion. The main food page covers sodium and calcium alongside oxalate. Purslane comes in at 248 mg oxalate per 1 cup (Avoid) in the measured database.