Is Grapes (Red or green) Safe for Kidney Stones? (Safe)
mg oxalate
per serving
Serving: 1/4 cup (37 g)
Verdict: 🟢 Safe
Per 100g: 9 mg
Data: Harvard T.H. Chan SPH (2024)
Here's the takeaway: Grapes (Red or green) earns a Safe rating (🟢) at 6 mg oxalate per serving. Being under 25 mg means it fits comfortably in everyday eating. Keep your usual habits — adequate fluids and calcium in meals — and Grapes (Red or green) poses no special concern.
Putting Grapes (Red or green) in context: it lands well below the category average of 21 mg. In the database, 89% of fruits (101 of 113) fall in the 🟢 Safe group (under 25 mg oxalate/serving). The typical fruits here averages 21 mg oxalate per serving, so Grapes (Red or green) runs 72% below that baseline. That places it among the lower-oxalate options 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 fruits rated Safe for a full side-by-side.
Why does the safe threshold matter?
The 25 mg line is the reference point clinicians use to separate everyday foods from ones that need caution. Every value on this page traces back to Harvard's 2024 lab analysis, so the threshold is applied to measured data rather than estimates. For Grapes (Red or green), the measured oxalate value is 6 mg per 1/4 cup (Safe).
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, Grapes (Red or green) measures 6 mg per 1/4 cup, rated Safe.
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. For context, Grapes (Red or green) measures 6 mg per 1/4 cup, rated Safe.
Should I also check sodium and calcium?
Definitely. Oxalate is only part of the story — high sodium raises calcium in urine, and dietary calcium (from food, not pills) binds oxalate in the gut. The food's main page lists both, so it's worth checking before you plan around it. Grapes (Red or green) comes in at 6 mg oxalate per 1/4 cup (Safe) in the measured database.