Quinoa is a moderate-oxalate food. A cup of cooked quinoa contains about 54 mg of oxalates, which is meaningful but not extreme compared to truly high-oxalate foods like spinach (hundreds of milligrams per serving) or even buckwheat (133 mg per cup). Whether that amount matters for you depends on your overall diet and kidney stone history.
How Quinoa Compares to Other Grains
Among grains and grain-like foods, quinoa sits in the middle of the pack. Here’s how a typical serving stacks up, based on data from the Harvard School of Public Health:
- White rice (1 cup cooked): 3.8 mg
- Brown rice (1 cup cooked): 18.7 mg
- Oats (1 cup cooked): 0 mg
- Quinoa (1 cup cooked): 54.4 mg
- Buckwheat groats (1 cup roasted): 132.6 mg
Rice and oats are clearly lower-oxalate options. But quinoa delivers less than half the oxalates of buckwheat, and it’s nowhere near the levels found in high-oxalate vegetables like beets, rhubarb, or spinach, which can pack 500 mg or more per serving.
What This Means for Kidney Stones
People following a low-oxalate diet for calcium oxalate kidney stones typically aim to stay under about 100 mg of oxalates per day. A cup of cooked quinoa uses up roughly half that budget in a single food, which is worth keeping in mind if you’re tracking carefully.
That said, the National Kidney Foundation actually lists quinoa in the “Recommend” column of its meal planning guide for people with calcium oxalate stones. This may seem surprising given the moderate oxalate count, but it reflects the fact that quinoa also provides substantial calcium, magnesium, and other nutrients that can help offset oxalate absorption. The overall quality of your diet matters more than any single food’s oxalate number.
Cooking Reduces Oxalate Levels
How you prepare quinoa makes a difference. The Oxalosis and Hyperoxaluria Foundation lists two values that illustrate this: cooked quinoa has about 61 mg of oxalate per 100 grams, while quinoa that’s been boiled for 30 minutes drops to 44 mg per 100 grams. That’s roughly a 28% reduction from extended boiling, since some oxalates leach into the cooking water.
Rinsing quinoa thoroughly before cooking and soaking it for a period beforehand can further reduce oxalate content. Most people already rinse quinoa to remove its bitter outer coating (called saponins), so you may be lowering oxalates without even trying. For the greatest reduction, rinse well, soak for a few hours, drain the soaking water, then cook with fresh water. The cooking liquid will pull out additional oxalates, so draining any excess water after cooking helps too.
Serving Size Matters
The numbers above are for a full cup of cooked quinoa, which is a generous portion. Many people eat closer to half a cup as a side dish. At that amount, you’re looking at roughly 27 mg of oxalates, which fits comfortably into a low-oxalate eating plan alongside other low-oxalate foods throughout the day.
If you’re pairing quinoa with calcium-rich foods like yogurt or cheese, that also helps. Calcium binds to oxalates in your digestive tract, preventing them from being absorbed into your bloodstream and eventually reaching your kidneys. Eating calcium and oxalates together at the same meal is one of the most practical strategies for managing oxalate intake without eliminating foods you enjoy.
Lower-Oxalate Swaps
If you’re on a strict low-oxalate diet and want to minimize your intake from grains, white rice and oats are the safest choices. White rice contributes under 4 mg per cup, and cooked oatmeal registers at essentially zero. Brown rice at about 19 mg per cup is another reasonable option that still delivers more fiber and nutrients than white rice.
For most people who are simply trying to keep oxalates in check without following a strict medical protocol, quinoa in normal portions is a perfectly reasonable choice. Keep servings moderate, rinse and cook it well, and pair it with calcium-rich foods to reduce how much oxalate your body actually absorbs.