Almonds, pine nuts, and Brazil nuts are the highest-oxalate nuts, with soluble oxalate levels ranging from about 490 to 560 mg per 100 grams. That’s significant when you consider that a standard low-oxalate diet aims to keep total intake around 100 mg per day. A single ounce of almonds (roughly 22 kernels) contains about 122 mg of oxalate, enough to exceed that daily target on its own.
The Highest-Oxalate Nuts, Ranked
Not all nuts carry the same oxalate load. The differences are large enough that swapping one nut for another can dramatically change your daily intake. Here’s how the most common varieties compare, based on laboratory analyses of soluble oxalate (the form your body actually absorbs):
- Almonds: ~539 mg soluble oxalate per 100 g, or about 122 mg per ounce. The single highest-oxalate nut most people regularly eat.
- Pine nuts: ~496 mg soluble oxalate per 100 g. Often used in pesto and salads, where a couple of tablespoons can add up quickly.
- Brazil nuts: In the same high range as almonds and pine nuts, roughly 492 to 557 mg per 100 g.
- Cashews (roasted): ~225 mg soluble oxalate per 100 g, or about 49 mg per ounce. Moderate rather than high.
- Peanuts (roasted): ~147 mg soluble oxalate per 100 g, or about 27 mg per ounce. The lowest of the commonly eaten options listed here.
The National Kidney Foundation specifically flags almonds, mixed nuts (without peanuts), and sesame seeds as high-oxalate choices to be cautious about if you have a history of calcium oxalate kidney stones.
Why Soluble Oxalate Matters More Than Total Oxalate
Oxalate in food exists in two forms: soluble and insoluble. Insoluble oxalate is already bound to minerals in the food itself and passes through your digestive tract without being absorbed. Soluble oxalate dissolves in your stomach and intestines, enters your bloodstream, and eventually reaches your kidneys, where it can combine with calcium to form crystals.
This distinction matters because some nuts look similar in total oxalate but differ sharply in how much your body actually takes in. Pine nuts, for instance, have an unusually high level of intestinal soluble oxalate (about 581 mg per 100 g), meaning a large proportion of their oxalate is available for absorption. Almonds have high gastric soluble oxalate but lower intestinal soluble levels (about 223 mg per 100 g), so less of it may ultimately reach the kidneys. Both are still considered high-oxalate foods, but the real-world impact can vary.
Lower-Oxalate Nuts You Can Swap In
If you’re watching your oxalate intake, you don’t have to give up nuts entirely. Several options fall well below the threshold that would cause concern. Peanuts, despite being technically a legume, deliver only about 27 mg of oxalate per ounce. Pecans also fall into the lower-oxalate category, with soluble oxalate levels in the same range as cashews and peanuts (under 250 mg per 100 g). Macadamia nuts and walnuts are generally considered lower-oxalate as well, though exact values vary by source and growing region.
Cashews sit in a middle zone. At about 49 mg per ounce, they’re roughly a third the oxalate load of almonds. For someone on a 100 mg daily oxalate limit, a small handful of cashews leaves room for oxalate from other foods throughout the day. The same serving of almonds would not.
How Calcium Blocks Oxalate Absorption
One of the most practical things you can do if you eat higher-oxalate nuts is pair them with calcium-rich foods. Calcium binds to oxalate in the gut before it can be absorbed into the bloodstream, forming an insoluble compound that passes harmlessly through digestion. This means the oxalate never reaches your kidneys.
Dairy products are the most effective pairing. Having yogurt, cheese, or milk at the same meal or snack where you eat nuts reduces the amount of free oxalate your body takes in. The key word is “same meal.” Calcium consumed hours later won’t catch the oxalate in your digestive tract. If you don’t eat dairy, a calcium supplement taken with your meal can serve the same purpose, though food sources tend to work better for stone prevention overall.
This also explains a counterintuitive piece of dietary advice: people with calcium oxalate kidney stones should not restrict calcium. Eating too little calcium actually increases stone risk, because there’s less calcium in the gut to bind oxalate before it’s absorbed.
Putting the Numbers in Context
A low-oxalate diet typically caps intake at about 100 mg per day. To stay within that limit, a single ounce of almonds would use up your entire daily allowance. An ounce of peanuts, by contrast, uses about a quarter of it. That difference is what makes nut selection genuinely meaningful for people managing kidney stone risk.
Portion size also plays a bigger role than people expect. A small sprinkle of pine nuts on a salad (maybe half an ounce) is a very different proposition from eating a full cup of trail mix loaded with almonds. If you enjoy higher-oxalate nuts occasionally and in small amounts, especially alongside calcium-rich foods, the practical risk is lower than the raw numbers suggest. The concern is really about daily, concentrated intake: almond flour baking, almond butter as a staple, or regular large servings of mixed nuts with almonds as the base.
Roasting, blanching, or soaking nuts can modestly reduce their oxalate content by leaching some soluble oxalate into the cooking or soaking water, but the effect isn’t dramatic enough to turn a high-oxalate nut into a low-oxalate one. Almonds soaked overnight are still high-oxalate almonds.