I did not even know what oxalates were until reading this Mercola article. It is the paradox of many healthy foods that they contain damaging oxalates. Yes, it does raise the question of what one is to eat for optimal health.
https://articles.mercola.com/sites/articles/archive/2019/11/10/oxalic-toxicity.aspx
• “Oxalic acid or oxalates are very tiny molecules that bind minerals like calcium and form crystals. It is found in a variety of seeds, nuts and many vegetables. It’s only two carbons and four oxygen molecules. It’s a highly reactive compound that is attracted to positively charged minerals
• Oxalates not only can cause kidney stones (calcium oxalate kidney stones) but also may be responsible for a wide variety of other health problems related to inflammation, auto-immunity, mitochondrial dysfunction, mineral balance, connective tissue integrity, urinary tract issues and poor gut function
• Oxalic acid can harm glandular function, connective tissue function, neurological function and the function of the tissues of excretion, particularly the kidneys and bladder
• Having a damaged gut lining will increase your absorption of oxalates. An inflamed or damaged gut lining is a very common problem, thanks to frequent antibiotic use and the presence of a number of chemicals in our food supply, including glyphosate. Other plant compounds such as phytates and lectins (such as gluten) can worsen gut health and exacerbate the impact of oxalates
• Tissue destruction, fibromyalgia and autoimmune diseases such as rheumatoid arthritis and lupus are all issues that can be related to oxalates
https://www.youtube.com/watch?v=K-CWtmYwakI&feature=emb_title
““Calcium has a particular love of oxalate, and vice versa. The two of them seek each other out quite easily. We often see very abundantly the calcium oxalate form of oxalate. We see it in the plants. The plants form crystals and have the smaller individual ions and nanocrystals. But they do form these bigger constructions, these kinds of plant pyramids, rocks and sticks and diamonds and things that the plants make, probably deliberately for many … plants are making use of oxalate for self-defense. In the body, you’re going to see these other forms … A molecule that has less strong a bond — potassium oxalate, sodium oxalate and so on — those are the soluble forms. When you see oxalate in nature, you see the big calcium oxalate crystals — that’s the same thing that the kidney stone is made of. The major ingredient of the classic kidney stone is oxalate. Unfortunately, in our parlance in medicine, we think of it as calcium … We just generalize to calcium because there are multiple types of calcium stones. But in the case of oxalate stones and oxalates causing calcification in the body, the oxalate part gets sort of dropped.
Medicine is not taught that you need the substrate to make a kidney stone. You need to provide enough oxalic acid or oxalate, soluble oxalate, the potassium oxalate, the sodium oxalates and so on. You can provide enough of that to perform this calcification in the kidneys and elsewhere in the body. The plants that we’re eating have these oxalate crystals. The big ones just cause abrasion … They’re very small, but at the cellular level they’re quite big and abrasive. They just cause mechanical damage … These soluble oxalates are the ones that easily — because they’re so tiny — pass through in between cells. Just with passive transport, we end up absorbing oxalates. The amount we absorb depends on a lot of factors, especially the health of our digestive tract. Those of us with any inflammation in the digestive tract are more prone ... to absorbing more of that soluble oxalate and even nanocrystals of calcium oxalate. At least 1% of calcium oxalate from food is also absorbed, in addition to the soluble oxalate. But you see, soluble oxalate is not content being potassium oxalate. It would much rather be calcium oxalate, iron oxalate or magnesium oxalate. Right away, it starts grabbing minerals. It starts messing with mineral metabolism. It even can create bouts of acidosis.”
Examples of high-oxalate foods are potatoes, peanuts, nuts, spinach, beets, beet greens, chocolate, blackberries, kiwi, figs, black beans, buckwheat, quinoa and whole grains. It is quite a list, and cutting all of these out is possible, and perhaps necessary for people suffering from oxalate stress. At least try to minimise consumption of the heavy hitting oxalates, such as spinach. Here is a more detailed list of high oxalate foods:
https://www.webmd.com/kidney-stones/kidney-stones-food-causes#1