Oxalates In Greens: Should You Be Concerned?

We have been told since childhood that eating our greens is important.

Because of this, it may be surprising to hear that many leafy greens contain potentially harmful compounds called oxalates. (Source)

An oxalate, or oxalic acid, is an antinutrient. It binds to healthy minerals and forms an unstable compound so that the mineral can not be absorbed.

This can lead to nutrient deficiency along with other health complications in individuals with high oxalate levels.

Fortunately, you can reduce your oxalate consumption without cutting back on your fruits and veggie intake.

This article covers what you need to know about oxalic acid. It covers topics like what is oxalate, foods that are low in oxalates, and how to know if you are at risk of high oxalate levels. Read now and discover the truth about oxalates in greens.

What Are Oxalates?

We get it. An antinutrient sounds scary, especially if you eat your greens regularly and are proactive about your health.

You might be asking, “What is oxalate, and why should I be worried?”

An oxalate, or oxalic acid, is a naturally-occurring compound. It can be found in various plants, including leafy green vegetables, cocoa, nuts, fruits, and seeds.

When we eat certain plants, oxalates enter our system. They bind to minerals and form compounds such as iron oxalate and calcium oxalate.

These compounds can make it difficult for the body to fully absorb minerals from the food we eat, which can negatively affect your health.

It can lead to nutrient deficiency, kidney stones, and other health complications.

But before you throw away all your plant-based foods, you should know that the body can produce oxalic acid on its own. These oxalates come in various shapes and forms and vary in size.

Also, for most people, oxalates are passed through the urine or stool without issue. Significant damage from oxalic acid is rare and only occurs in specific cases.

Where Do Oxalates Come From?

Oxalates typically come from two places: plants and our bodies. 

Plants naturally produce oxalates, although there is no definitive reason why. Some research suggests that plants do it as an act of self-defense and to encourage seed germination. (Source)

So when we eat certain plants, we are also letting oxalates enter our system.

However, you will not become oxalate-free by never eating plant-based foods again.

This is because our bodies can produce oxalates all on their own. Even essential vitamins, like vitamin C, can convert into oxalates when digested.

Luckily, most healthy people can pass these antinutrients easily through their urine or stool without issue. (Source)

What Foods Are Oxalates Found In?

Here’s the bad news. There are not many greens low in oxalates.

In fact, all of the foods included in our high oxalate list are plant-based.

However, there are some plant-based foods and plenty of other non-plant foods that are low in oxalates.

Foods Low In Oxalates

• Non-plant-based foods, including dairy, eggs, meat, oils, and fats
• Some plant-based foods, including cabbage, avocado, cauliflower, cucumber, lettuce, and green peas
• Fungi, including mushrooms

Food High In Oxalates

• Some grains including whole grain bran
• Some nuts including peanuts and almonds
• Some seeds including sesame seeds
• Leafy green vegetables like spinach
• Spices like turmeric, cumin, and black pepper
• Potatoes, beets, blackberries, and kiwi
• Chocolate

If your everyday diet includes one or more items on the “high oxalate” list, there is no need to go clean out your pantry. Most foods with high oxalate levels are very healthy for you. 

That being said, being mindful of your oxalate intake and its associated risks could benefit your health in the long run.

Are Oxalates Harmful?

So, is oxalate bad for you?

It is possible, but the effect that oxalic acid has on healthy individuals is minimal.

Here is a look at the main health concerns associated with oxalates.

1. They Reduce Mineral Absorption

When consumed, oxalates attach to minerals such as calcium, magnesium, iron, and zinc in the GI tract. This is especially the case when oxalate consumption is combined with fiber. (Source)

This bind makes the mineral useless and prevents it from being absorbed by the body. This means that your body may be getting less calcium, magnesium, iron, and zinc than it should be.

In other words, your body is not getting the maximum benefit from the food you eat.

Because minerals play such an important role in our health, reduced mineral absorption may negatively impact your health. It can cause a deficiency that leads to an array of health complications.

It can also affect women disproportionately, as they require more calcium in their diet to maintain healthy and strong bones. (Source)

Research shows that calcium deficiency over time can increase your risk of developing osteoporosis, a bone disease that occurs predominantly in women. (Source)

That being said, mineral deficiencies in healthy individuals are rare.

There is no need for concern unless you are experiencing symptoms of mineral deficiency, like abdominal pain, bloating, weakened immune system, or loss of appetite.

2. They May Cause Kidney Stones

The presence of calcium and oxalates in the urinary tract is considered normal.

However, the oxalates can sometimes bind together and form crystals, which can then form kidney stones. (Source)

In fact, calcium oxalate is present in 80 percent of kidney stones. (Source)

Due to this, some health professionals recommend a low oxalate diet for people with a history of kidney stones. 

However, this is typically only recommended for people with high oxalate levels in their urine. (Source)

A low oxalate diet is not necessary for most healthy individuals.

What Puts Me At Risk Of Oxalate Harm?

Some factors, including diet and medical history, can put you at an increased risk of having high oxalate levels. 

1. You Follow A Vegan Or Vegetarian Diet

If you follow a vegan or vegetarian diet, you probably eat a lot of plants. This means you are likely consuming increased amounts of oxalic acid.

While this is not innately harmful (plant-based foods are healthy, after all), it may hinder your body’s ability to fully absorb minerals. (Source)

This could lead to mineral deficiency, but the risk is small, especially if you eat an otherwise well-rounded diet.

2. You Have A Preexisting Health Condition

Having a pre-existing medical condition could put you at an increased risk of high oxalate levels.

This is especially true for people with gut-related health issues.

For example, research suggests that people with inflammatory bowel disease are more likely to develop a kidney stone in their lifetime. (Source)

In addition, studies show that people who underwent gut-related surgeries had increased oxalate levels in their urine. (Source) 

Lastly, people who are more susceptible to kidney stones may be at an increased risk of having high oxalate levels.

In sum, people with underlying conditions that affect the gut may be at an increased risk of high oxalate levels.

How Can I Tell If Oxalates Affect Me?

Here’s some more bad news: there is no definitive way to tell if oxalates affect you.

You can take a test that detects how much oxalate is in your system.

However, these levels can fluctuate, and it’s not a great indicator of whether the oxalic acid is causing any harm.

Everyone responds differently to oxalates. How you feel day to day is probably the best window into examining how your oxalate levels are affecting you.

If you have a history of kidney stones or regularly experience digestive issues, abdominal pain, fatigue, or have cloudy urine, it may be worth checking in with a health professional.

These symptoms could all indicate an unhealthy amount of oxalates in your body.

However, for most healthy individuals, oxalates are not a need for concern.

Are Green Powders Safe From Oxalates?

Green powders offer a wide range of health benefits. They can boost your energy levels, strengthen your immune function, and improve your overall health.

They are a great way to get more nutrients in your diet and meet your recommended daily veggie intake, regardless of your schedule or lifestyle.

However, the supplement industry is not FDA-regulated, which can make some green powders unsafe.

Some poorly made green powders can cause side effects like allergic reactions, interact with medications, and contain harmful substances.

In addition, many supplement companies use proprietary blends, which allows them to hide what is actually in their product.

For instance, a company can say its proprietary blend contains buzzword ingredients like superfoods, adaptogens, and amino acids, but it will not state how much of each ingredient is in the blend.

Therefore, you could be paying for an expensive product that only has 1% active ingredients. It may also contain harmful ingredients that the company is not required to tell you about. 

Heavy metals are one harmful substance to look out for. Heavy metals are often found in soil and the vegetables that grow in them.

Copper, cadmium, and lead pose the most harm to your health, and they have all been found in some soil and crops. (Source)

If greens powder is made from contaminated vegetables, the powder will also be contaminated. Over time, these substances can cause bone fragility, kidney disease, and even cancer.

Since the FDA does not regulate supplements, most brands are not required to check for heavy metals. This means some green powders can include cancer-causing heavy metals, which does far more harm than good for your body.

Since green powders contain mostly plant-based ingredients, they can also contain oxalates, and the company is not required to test for them.

It is on the consumer to read the fine print on supplement labels and sort through the proprietary blends and pseudoscience claims to find a safe, high-quality green powder.

How Can I Protect Myself From Oxalates?

The best way to protect yourself from oxalates and other harmful ingredients in green powder supplements is by only buying supplements that are third-party tested.

Third-party testing ensures that the supplement is free of harmful substances like heavy metals and oxalates. It can also verify the purity of each ingredient.

Consumer Labs is a company that reviews powders to confirm their safety. You can also check out a site like Consumer Reports to read reviews and get transparent information on different supplements.

For these reasons, we recommend Supergreen Tonik as your go-to greens powder. It checks off all the boxes of what to look for in a green powder supplement.

It is third-party tested and made in the USA using sustainably sourced ingredients. It also uses transparent ingredients with no proprietary blends, so you know exactly what to expect in each scoop. It also has a large amount of positive reviews which can back up its credibility.

Final Thoughts

Oxalates are compounds produced by plants. When consumed, they can bind to minerals and make them unusable to the body.

This means that your body can not absorb some of the minerals you consume or get their benefits.

While rare, high amounts of oxalate in the body can lead to mineral deficiency and other health complications.

It may also increase the risk of developing kidney stones in sensitive individuals. 

However, cutting out plant-based foods from your diet is not necessary. In fact, it can be straight-up unhealthy.

Oxalates are not a health concern for most healthy individuals. They typically pass oxalates through the urine or stool without complication.

If you are still concerned about your oxalate levels, there are ways to manage your intake. You can reduce your intake of food from the “high oxalate” list and swap them for “low oxalate” foods. Using a green powder that third-party tests its ingredients for purity and potency can also decrease your oxalate intake.

Kelly McGeehan, MSc

Kelly McGeehan is a freelance health and wellness writer based in Oahu, Hawaii. She’s a proud former Owl, graduating with her Master’s degree in English from Temple University. She is also a competitive runner with 15 years of mileage under her spikes. Kelly combines her background in healthcare, wellness, and fitness with her writing background to create content for various health-related businesses.

She brings a passion for holistic health to the keyboard and writes to inspire others to live happier, healthier lives. In her free time, you’ll find her reading on the beach or training for her next half marathon.