Are blackberries high in oxalate?
Yes. High, 42 mg per 1 cup
One study at 42 mg, 144 g serving
Lower-oxalate swap: Strawberries, grade A, about 3.4 mg per 1 cup.
Blackberries are high in oxalate: about 42 mg per 1 cup, which is 84% of the 50 mg a day many stone clinics aim for, or 42% of the 100 mg others allow.
If your doctor has put you on a low-oxalate diet, eat it with something high in calcium, like milk, yogurt or cheese. Calcium in the same meal binds oxalate in the gut, so less of it reaches your urine. How much calcium, and what if you don't eat dairy.
50 or 100 mg a day: which target is yours
Where this number comes from
Each row is one published measurement, converted to a 144 g serving (1 cup). The grade and the range use the rows prepared the way the serving is eaten, and take the middle. How the grades work.
| Per serving | Per 100 g | Preparation | Source |
|---|---|---|---|
| 42 mg | 29.2 mg | Raw (n=4) | Hönow and Hesse, 2002 [1] |
By Oliver Silen · Data checked November 2, 2026 · Not medical advice
