Is Swiss Chard Red Safe for Kidney Stones? (Avoid)
mg oxalate
per serving
Serving: 1 cup (36 g)
Verdict: 🔴 Avoid
Per 100g: 1167 mg
Data: Harvard T.H. Chan SPH (2024)
Here's the takeaway: Swiss Chard Red is a Avoid food (🔴) at 420 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 Swiss Chard Red 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 Swiss Chard Red runs 1454% 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. For Swiss Chard Red, the measured oxalate value is 420 mg per 1 cup (Avoid).
Can I eat this food every day?
For Safe foods (under 25 mg/serving), daily use is generally fine. Caution and Avoid foods work better as occasional items — rotate them with safer options so no single high-oxalate food becomes a habit. For context, Swiss Chard Red measures 420 mg per 1 cup, rated Avoid.
Where does the oxalate data come from?
The numbers come from Harvard T.H. Chan SPH's 2024 laboratory measurements, published through the OHF database. Direct lab analysis, which is why they're treated as the reference values for food oxalate. Swiss Chard Red comes in at 420 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. For context, Swiss Chard Red measures 420 mg per 1 cup, rated Avoid.