Maybe you’ve heard about oxalates in passing, or maybe you’ve read conflicting info online.
Either way, you’re confused about what to believe. Are they really as dangerous as people say?
You can probably guess that this is a complex conversation — and there’s no way I can cover everything here.
But I still want to dive into the most recent research so you can come to your own conclusions.
But first: a quick definition
Oxalates are plant chemicals that bind to minerals in your body. They’re sometimes referred to as ‘anti-nutrients’ since they can stop your body from absorbing key minerals like calcium.
You can find oxalates in leafy greens like spinach, rhubarb, and chard. You’ll also find high levels in ketogenic favorites like almonds, black tea, and chia seeds.
Studies show that 22 grams of oxalates (or 0.77 ounces) is enough to kill an adult human. Of course, reaching this number requires a relatively extreme intake — the equivalent of 10 pounds of rhubarb or ~11 cups of cooked beets.
That said, you don’t need to consume that much oxalic acid before feeling its effects. Studies show that a high oxalate level (sometimes referred to as hyperoxaluria) is directly connected to:
- Kidney stones
- Mitochondrial dysfunction
- Inflammation, potentially resulting in arthritis
- The development of cardiovascular disease
- Poor immune response, which opens the doors to autoimmune conditions
Your body usually captures and releases oxalates by flushing them out in your urine. However, too much too quickly can get trapped in your body, which can lead to serious consequences.
Both sides of the oxalate debate
Some people will tell you that oxalates aren’t a problem in a healthy diet. Others will tell you to avoid oxalate-rich food entirely.
The truth, I feel, lies somewhere in the middle.
Here is an overview on both sides so you can make your own decision.
The ‘oxalates are no big deal’ group
Since oxalates are typically flushed out in urine, well-hydrated people are less susceptible to their side effects. They also bind to calcium-rich foods like yogurt and milk, which is a common part of most people’s diets. Cooked foods are much lower in oxalates as well — steaming removes up to 46% of soluble oxalates, while boiling removes up to 87%.
Proponents also argue that avoiding oxalate-rich foods could cause significant nutritional problems. Using the American food pyramid as an example, it would be hard to meet daily vegetable recommendations while avoiding spinach, Navy beans, tofu, and berries.
Their ultimate argument is that oxalates ‘aren’t a problem’ for most diets. In the words of one study, “the occasional consumption of high oxalate foods as part of a nutritious diet does not pose any particular problem.”
The ‘oxalates are dangerous’ group
Most doctors recommend that high-risk individuals keep their oxalate consumption under 50mg per day. Many people, however, consume far more than this — around 214mg per day for men and ~185mg per day for women.
Considering oxalates build up slowly over time, this could eventually become disastrous to heart, joint, and brain health.
If too many oxalates build up in your body, you might experience a phenomenon known as ‘oxalate dumping.’ As the body rapidly eliminates your oxalate stores, you experience swelling, inflammation, nausea, and other symptoms of illness.
Oxalate dumping remains poorly understood, but it is widely reflected in anecdotal evidence. And considering there’s been a rise in kidney stone diagnoses — most alarmingly for younger and younger patients — some people choose to avoid oxalate foods entirely and stick with animal-based diets such as ketovore and carnivore.
Of course, your risk factors are higher if you eat whole, real foods other than animal protein. Considering vegetarians are 31% more likely to suffer from kidney stones, plant-based diets may carry a higher risk.
So how do you be mindful of oxalates in your diet?
It’s clear oxalates have some impact on the human diet, particularly when eaten in excessive amounts.
The real trick is learning how to balance them in your diet.
If you’re on a carnivore or lion diet, this probably won’t be a concern for you. But if you’re following a keto, vegan, or vegetarian diet, the following tips may be helpful.
Keep an eye on high-oxalate foods
For most people, these are easy-to-overdo foods like almonds and almond flour, nut butters, and spinach.
However, you should also be mindful of foods like:
- Soy
- Potatoes
- Navy beans
- Black or green tea
You’ll also find oxalates in beets, raspberries, and dates, but for most people, these are occasional treats rather than weekly foods (if they’re in your diet at all).
Just remember: not all foods that are low in oxalates are good for your metabolic health. White rice and corn syrup are technically on the ‘safe side,’ but they can also wreak havoc on your heart health and blood sugar.
Increase your calcium intake
Since calcium can bind to oxalates in the gut, it’s worth upping your consumption if you’re concerned about high intakes.
If you don’t want to supplement with calcium capsules, you could eat more yogurt, broccoli, collard greens, and fatty fish like sardines. You could also drink more dairy milk or incorporate cheeses like cheddar or mozzarella.
You should also know that a high-protein diet increases the body’s calcium absorption. Eating fewer processed carbohydrates and more animal protein (including eggs) is a great way to heal and protect your gut.
I realize this advice isn’t all that helpful if you follow a vegetarian or vegan diet. For this reason, I’d greatly encourage you to speak with a dietician about how to maintain your metabolic health without undernourishing your body.
Keep yourself hydrated
I don’t just mean drinking lots of water. You also need to get enough electrolytes, which should include salt, potassium, and magnesium, among other minerals.
The ‘right’ amount of water should ultimately boil down to your individual needs. That said, a very rough rule of thumb is 0.5 ounces per pound of body weight. So if you’re 150 pounds, that’s 75 ounces of water (a little over half a gallon).
This number should go up if you exercise or sweat frequently.
Know your risks
No matter where you stand in the oxalate debate, it’s a good idea to know your propensity for side effects.
For example, if you have a high risk (or a history) of kidney stones, eating lots of high-oxalate food isn’t a good idea.
You may also want to be cautious if:
You have a previous history of broad-spectrum antibiotic use
You’ve had a Roux-en-Y gastric bypass surgery
You heavily supplement with vitamin C
You can get tested for oxalates by your healthcare provider, but depending on your doctor, it might not be easy to get it ordered. You can always purchase oxalate test strips over the counter — but I’d recommend scheduling a full blood panel anyway.
Learning more about oxalates
As you’ve seen, there’s a lot of nuance in the oxalates debate. Certainly more than can be covered here.
The bad news is, it’s just the tip of the iceberg. The good news is, we’re seeing new research all the time.
I highly recommend staying current with studies by following people and publications you can trust. Of course, this doesn’t necessarily mean believing everything at face value. I recommend joining active health groups and asking as many questions as you can.
Looking to join the conversation? You’re welcome to come find me on X.
