If you’ve been reading this blog long enough, then you know that I’m all about healthy eating. Maybe as part of your healthy eating plan and getting in your seven-a-day portions of goodness, you’ve been blending vegetables and fruits into a green juice or smoothie. But could your newfound love for certain leafy greens be causing you more harm than good? Let’s find out more by first answering a question you may have: “What are oxalates?”
WHAT ARE OXALATES?
Oxalates are one of many naturally occurring compounds found in plants. Plants use them to regulate their own internal mineral content and help defend against predators. Our bodies absorb oxalates as a result of the consumption of plant-based foods.
Humans also produce them when breaking down vitamin C. In this instance, oxalates are a toxic end product that needs to be removed from the body as waste. They circulate in the blood as oxalic acid.
WHAT ARE THE DANGERS OF OXALATES?
An accumulation of oxalates in the body — either from your diet or your body having difficulty removing them — can cause many health problems.
When oxalates bind to calcium, they can form calcium oxalate crystals. These crystals prevent calcium from being absorbed and utilized and can contribute to diseases such as osteomalacia and rickets. They can also travel through the body, causing muscle pain. And if they make it to the kidney they can cause kidney stones.
The main reason for the dietary concern is kidney stones. 80% of kidney stones are calcium oxalate stones, meaning that calcium and oxalates bind together in the kidney to form the stones. If you are prone to kidney stones, it would be best to avoid foods high in oxalates.
Oxalates also bind to minerals such as iron or magnesium, making them no longer available for absorption. This is why they are called anti-nutrients; they can cause a deficiency even when you are eating plenty of mineral-rich foods.
WHAT ARE THE SYMPTOMS OF HIGH OXALATES?
Oxalates are directly correlated with the formation of the most common type of kidney stones. In fact, approximately 80% of all kidney stone cases are caused by calcium oxalates.
If oxalate levels in the body become high, the natural response of the body is to try to store some away in different organs, like the thyroid. As oxalate crystals grow in the thyroid they can begin to cause a malfunction and ultimately lead to hypothyroidism.
Oxalates can interfere with normal connective tissue maintenance and repair, leading to connective tissue problems like fibromyalgia. Fibromyalgia is characterized by muscle and joint aches and pains throughout the body that don’t seem to have a physiological cause. This pain can compromise the sufferers' quality of life and can be accompanied by chronic fatigue, brain fog, hormone imbalance, insomnia, and headaches.
High oxalates can create systemic inflammation throughout the body. This keeps the immune system busy fighting the inflammation so that it is not functioning optimally. As a result, autoimmune conditions like rheumatoid arthritis and inflammatory bowel disease can get worse.
The symptoms and conditions that I’ve just mentioned may or may not have anything to do with high oxalates. That is because they can differ from person to person, and there is no recognizable symptom pattern that is a tell-tale sign.
However, shifting to a low-oxalate diet can provide relief from all these conditions and their symptoms.
Christine's Tip: If you want a more concise guide showing you how to identify whether you have an oxalate problem and a research-backed plan with recipes and handy food charts, then check out Toxic Superfoods by Sally K. Norton, a vitality coach, and health consultant.
MANAGING YOUR DIET: WHAT TO AVOID AND WHAT TO EAT
You will find oxalates — to some degree — in basically every healthy plant food. As a result, it’s impossible to avoid them entirely. But you shouldn’t want to! After all, if you gave up all of the oxalate-containing foods, you’d also be giving up high-fiber, phytonutrient-rich foods.
It’s important to know which foods are oxalate-rich (and thus avoid them), and which foods are low in them (so that you can swap them for high-oxalate foods).
For reference, high-oxalate foods typically have over 100 mg in an average serving, and can even reach up to 800 mg per serving. On the other hand, foods low in oxalates typically have under 4 mg per serving. In fact, a low-oxalate diet is typically considered reducing them to below 50 mg total for the day.
Christine’s Tip: Some people find the OxaBrow and Oxalator apps useful when meal planning to help adjust the oxalate content of your meals. The Oxabrow app gives you the amount per serving while the Oxalator categorizes foods from low to high. But there is a lot of conflicting advice about what foods to include or avoid. Personally, I am following Sally K. Norton's approach on what foods to include and avoid. You can download her useful, free guide HERE.
HOW TO REDUCE OXALATES IN FOODS
If you find that you need to reduce the number of oxalates in your diet or just want to exercise caution, here are some useful tips.
1. Eat a low oxalate diet as much as possible. This is one of the most important steps you can take. And fortunately there are lots of low oxalate alternatives to all of your favorite high-oxalate foods.
2. Eat calcium together with medium oxalate foods. Eating around 800-1,000 mg of calcium per day can help to offset some of the potential effects of oxalates that can otherwise lower your calcium levels. But I'm not encouraging you to eat more oxalates than needed, since keeping your overall oxalate intake low is the best approach.
3. Increase your magnesium intake. Magnesium can help reduce oxalate absorption when taken at around the same time as oxalate-containing foods. A magnesium supplement can be taken. Or you can consume magnesium-rich foods like low oxalate legumes such as lentils or black eyed peas or low oxalate dark leafy greens like bok choy or mustard greens.
4. Cook oxalate-containing foods before eating them. Studies have shown that boiling raw vegetables that contain oxalates reduced the compound by 30-87%. However, steaming only reduced them by 5-53%. It’s important to note that roasting, grilling, or baking may have little to no effect. Lately I've been boiling vegetables such as Brussels sprouts to help reduce their oxalate content.
5. Stay hydrated. Drinking enough fluids can help flush out oxalates and prevent dehydration, which can contribute to the formation of kidney stones in some people.
FREQUENTLY ASKED QUESTIONS
What are oxalates and why are they bad for your body?
When oxalates accumulate in the body, either from a high oxalate diet or your body having difficulty removing them, they can cause many health problems. Tiny oxalic acid crystals in the muscle and connective tissues may cause muscle aches and pain. High oxalates can also lead to kidney stones, gout, oxidative damage, glutathione depletion, and increased inflammation.
What are the symptoms of high oxalates?
Oxalates can accumulate in the body tissues causing inflammation, autoimmune diseases, interference with mitochondrial function and energy production, and can result in neurological damage.
This can result in unexplained symptoms like fatigue, poor sleep, heart arrhythmia, joint and muscle pains similar to fibromyalgia, brain fogs, eye pain, burning urine (interstitial cystitis), vulvar pain, and kidney stones.
One way to figure out if you have too many oxalates in your urine (and therefore need to limit how much you eat) is a 24-hour urine test. This test will quantify how much oxalates is in your urine. If it is elevated (usually more than 55 mg/day), this means you likely should cut back on how much you eat.
Alternatively, you can use the Organic Acids Test ordered in conjunction with a qualified practitioner to test your oxalate levels.
What foods are high in oxalates?
Foods high in oxalates include many leafy greens, beans, legumes, wheat products, soy, coffee, dark chocolate, certain grains, nuts, and nut butter, to name a few. However, foods don't come with labels outlining their oxalate content. As a result, it can be tricky knowing what to shop for and eat. A website that is pretty helpful is oxalate.org. It has a list of 750+ foods and their oxalate levels.