Oxalates are a type of naturally-occurring chemical found in many plant foods. They can bind with certain minerals, such as calcium and iron, in the digestive tract and prevent them from being absorbed by your body. Some people have trouble absorbing these minerals because they lack sufficient amounts of certain nutrients needed to break down oxalates.
Oxalates are naturally present in many foods and you can reduce your oxalate intake by avoiding high oxalate vegetables, supplements to reduce oxalates, and low oxalate bread. The following list shows the oxalate content of some common foods:
High Oxalate Vegetables
Rhubarb: 1 cup cooked = 40mg
Spinach: 1 cup cooked = 15mg
Kale: 1 cup cooked = 12mg
Swiss chard: 1 cup cooked = 10mg
Beets: 1 cup cooked = 9mg
Cauliflower: 1 cup cooked = 8mg
Beans (navy): 1/2 cup = 5mg
Asparagus: 4 medium spears = 5mg
Vegetables low in oxalates
Low-oxalate vegetables include:
Artichokes
Asparagus
Beets
Brussels sprouts
Cauliflower (including the leaves)
Collards, kale, and Swiss chard (cooked)
Cucumbers (peeled)
Eggplant (cooked)
Green beans (cooked)
Lettuce (butterhead or leaf lettuce) and other salad greens (cooked)
Okra (cooked)ParsleyPeppers, green or red, including hot peppers (raw or cooked), sweet bell peppers, and paprika. Potatoes are also low in oxalates when not eaten with their skins. Summer squash is also very low in oxalates. Tomatoes are low in oxalates when eaten raw or cooked but high in them when canned. Most fruits are low in oxalates except for berries such as strawberries, cranberries, raspberries and blackberries which may contain high levels of oxalic acid.
Oxalates are naturally-occurring chemicals found in many foods. They are normally present in the body, but can also be produced by some disease processes.
A high oxalate diet may increase the risk of kidney stones. However, there is no evidence that a low oxalate diet reduces the risk of developing kidney stones, or that people with a history of kidney stones should follow it.
Foods high in oxalates include:
spinach
beetroot (root)
rhubarb (stem and leaves)
Oxalates are naturally occurring substances found in plants, animals and humans. They are also the primary ingredient in many antifreeze products. The human body produces oxalate on a regular basis, but if you have too much of it in your system, it can cause health problems.
It is important to know how much oxalate you are consuming on a daily basis. If you have a kidney stone, hyperoxaluria or other medical problems related to excessive levels of oxalates in your system, it is best to avoid high-oxalate foods.
Asparagus – 1/2 cup (80 g) contains approximately 3 mg of oxalates
Broccoli – 1/2 cup (60 g) contains approximately 10 mg of oxalates
Brussels sprouts – 1/2 cup (50 g) contains approximately 9 mg of oxalates
Cabbage – 1/2 cup (85 g) contains approximately 10 mg of oxalates
High-oxalate vegetables include spinach, chard, beets, cabbage, rhubarb and sorrel.
Low-oxalate vegetables include Swiss chard, bok choy, collards, asparagus and summer squash.
Some low-oxalate fruits are strawberries and papayas. Low-oxalate foods also include potatoes, sweet potatoes and white rice.
Oxalates are naturally occurring substances in many foods that can bind to minerals like calcium and magnesium in the digestive tract and form crystals that cause kidney stones (1). The National Institutes of Health (NIH) estimates that about 10% to 15% of people who develop kidney stones have an underlying condition called primary hyperoxaluria (2). However, most people with kidney stones have no known risk factors for developing them.
People with primary hyperoxaluria may need to limit their intake of oxalates because they do not produce enough uric acid to help flush out excess oxalates from the body (3). A registered dietitian can help design a low-oxalate diet based on individual needs.
There are many supplements that help reduce levels of oxalates in the body. These include calcium, magnesium, vitamin C and vitamin B6. The best way to reduce oxalate levels is to avoid high oxalate foods.
Here are some low oxalate vegetables:
Asparagus
Broccoli
Cauliflower
Celery
Green beans (cooked)
Lettuce (Romaine)
Low oxalate foods are part of a low oxalate diet. The low oxalate diet is used to support normal kidney function and prevent kidney stones.
High oxalate foods can lead to problems with the kidneys, but sometimes they don’t. This is why it’s important to assess your own personal risks before making any changes to your diet based on someone else’s experience.
If you have been diagnosed with kidney stones, then the following foods may be high in oxalates:
Vegetables such as spinach, Swiss chard, beet greens and collard greens
Fruits such as strawberries, peaches and rhubarb
Nuts and seeds such as almonds, cashews and sesame seeds
Grains such as whole wheat bread and brown rice
Here are some foods high in oxalates:
Meats: beef, lamb, pork, poultry and fish (although some types of fish contain few oxalates)
Dairy products: milk, cheese and yogurt
Nuts and seeds: cashews, almonds and peanuts
Vegetables: beet greens, spinach, Swiss chard and rhubarb
Fruits: blackberries, cranberries and raspberries
The foods that are highest in oxalates are spinach, beet greens and rhubarb.
These foods also happen to be among the best sources of vitamin C. So how do you get the nutritional benefits of these foods without getting too much oxalate?
1. Cook your vegetables well and minimize the amount you consume. If you put spinach in a smoothie, blend it until it is a paste so that you are consuming only a small amount at once.
2. Eat your high-oxalate vegetables in moderation, or have them as part of a mixed meal that contains other vegetables with lower oxalate levels and/or fruit for additional water and fiber.
3. Take an oxalate supplement with meals or between meals if necessary (e.g., 500 mg per day). The supplement should contain calcium citrate or malate to counteract any negative effects on calcium absorption (see Calcium Supplements).
A low oxalate diet is a type of diet that may help reduce symptoms of kidney stones. It’s not clear exactly why this is, but it’s believed that certain foods can increase the amount of oxalate in the body.
Oxalate is a substance that can bind to calcium in the body and make it less available for use. Therefore, people with kidney stones may benefit from limiting oxalate-rich foods in their diet.