Pistachios are unlikely to cause kidney stones for most people. Among nuts, they rank surprisingly low in oxalate, the compound most commonly linked to calcium oxalate stones (the type responsible for about 80% of all kidney stones). A one-ounce serving of pistachios contains roughly 14 mg of oxalate and only about 67 mg of soluble oxalate per 100 grams, placing them in a completely different category from high-risk nuts like almonds.
How Pistachios Compare to Other Nuts
The oxalate gap between pistachios and other popular nuts is dramatic. Almonds contain around 539 mg of soluble oxalate per 100 grams, roughly eight times the amount in pistachios. Cashews come in at about 225 mg, hazelnuts at 212 mg, and pecans at 163 mg. Pistachios sit near the bottom of the list alongside chestnuts, with both containing fewer than 85 mg per 100 grams.
Researchers who studied the oxalate content across a wide range of nut varieties placed pistachios in the moderate-to-low risk group, alongside peanuts and pecans. By contrast, almonds, Brazil nuts, cashews, and pine nuts were flagged as nuts that should be consumed in moderation by people watching their oxalate intake. If you’ve been told to cut back on nuts because of kidney stones, pistachios are one of the safer choices you can make.
What Actually Matters: Soluble Oxalate
Not all oxalate in food contributes equally to stone risk. What matters most is “intestinal soluble oxalate,” the fraction your gut actually absorbs and sends to your kidneys. Pistachios contain about 76.5 mg of intestinal soluble oxalate per 100 grams. Compare that to almonds at 223 mg, and the practical difference becomes clear. Even though pistachios aren’t zero-oxalate, the amount that reaches your kidneys from a normal serving is relatively small.
Classic research on dietary oxalate and kidney stones identified eight foods that significantly increased urinary oxalate excretion: spinach, rhubarb, beets, nuts, chocolate, tea, wheat bran, and strawberries. But that finding lumped all nuts together. When you break them out individually, pistachios contribute far less oxalate than the category average suggests.
Pistachios and Uric Acid Stones
About 10% of kidney stones are made from uric acid rather than calcium oxalate. These form when uric acid levels in the blood or urine are elevated, often influenced by purine-rich foods like organ meats, shellfish, and alcohol. Pistachios don’t appear to raise this risk. A clinical study published in The Journal of Nutrition found that participants who ate one or two daily servings of pistachios actually experienced a decrease in serum uric acid compared to their baseline levels. The researchers suggested this may be because pistachios displaced higher-purine foods in the diet.
Protective Compounds in Pistachios
Pistachios contain phytate, a natural plant compound that actively works against stone formation. Phytate inhibits the crystallization of calcium salts in urine and soft tissues. Lab studies have shown that as little as 1.5 mg per liter of phytate in synthetic urine prevented the growth of calcium oxalate crystals. Pistachios contain meaningful amounts of phytate, with concentrations reported up to 490 mg per 100 grams in raw pistachios.
Research on people with a history of calcium oxalate stones found that those who followed a high-phytate diet showed a lower risk of forming new stones, with results comparable to treatment with potassium citrate, a standard medical therapy. So pistachios deliver a bit of oxalate, yes, but they also deliver a compound that counteracts stone formation.
How to Reduce Your Risk Further
If you’re prone to kidney stones but enjoy pistachios, a few simple habits can minimize any residual risk. The most effective strategy is pairing oxalate-containing foods with calcium-rich foods at the same meal. Calcium binds to oxalate in your gut, preventing it from being absorbed into the bloodstream and filtered through your kidneys. A glass of milk, a serving of yogurt, or cheese alongside your pistachios can make a meaningful difference. Restricting dietary calcium, counterintuitively, does the opposite: it frees up more oxalate for absorption and actually increases stone risk.
Staying well hydrated dilutes the concentration of oxalate and calcium in your urine, making crystals less likely to form. A standard one-ounce serving of pistachios (about 49 nuts, or 28 grams) keeps your oxalate exposure modest. Most dietary guidelines recommend 25 to 40 grams of nuts per day for general health, and staying within that range keeps pistachio-related oxalate well within safe territory for the vast majority of people.
Pistachios and Existing Kidney Disease
Kidney stones and chronic kidney disease are different conditions, and this distinction matters. If you already have impaired kidney function, the concern with pistachios shifts away from oxalate and toward their mineral content. A quarter-cup serving of pistachios contains about 150 mg of phosphorus and 290 mg of potassium. Healthy kidneys handle these minerals easily, but kidneys that are already struggling may not excrete them efficiently, leading to dangerous buildups in the blood. If you have diagnosed kidney disease (not just a history of stones), your dietary limits for these minerals will be different, and nut intake may need to be adjusted accordingly.