Oxalates and oxalic acid is a colourless, organic compound that occurs naturally in plants, animals and in humans. It can also be ingested from food and has the potential to bind with calcium, magnesium, iron, zinc and copper in our intestines to form oxalates - insoluble salts; thus interfering with the absorption of these minerals; and contributing to deficiency of the very minerals that are crucial for muscle growth and maintenance. Oxalic acid also can form insoluble salts (ie: calcium oxalates), which can crystallize and contribute to the formation of kidney stones.
Oxalic acid is found in greens such as spinach, swiss chard, beet tops, parsley and rhubarb. It generally increases as foods mature, producing increasingly bitter vegetables.Young, fresh vegetables such as baby spinach are less likely to have as high of an oxalic acid content as mature greens. Other foods high in oxalates are almonds, cashews, buckwheat, unhulled sesame seeds, tea, coffee, chocolate, textured soy protein, and beets. Low oxalate greens are lettuce, celery, watercress, asparagus, dandelion, and the members or the brassica family or cruciferous such as kale, bokchoy, collards, mustard greens, turnip tops, cabbage and arugula.
There’s a large degree of genetic variability in our ability to detoxify oxalates. Some people can consume far more oxalates without concern. Other contributors to one’s ability to tolerate oxalates include other dietary habits; such as a high protein diet – hence why bodybuilders ought to know about this.
What can you do?
Because oxalic acid is neutralized to some degree by heat, steaming or boiling our high oxalate veggies should be included in our regular meal plans. The flip side however, is that some of their minerals, vitamins and phytochemicals get leached out in the water when we boil or steam them – thus a combo of cooked and raw veggies in your diet is best. Likewise, nut and seeds can be soaked prior to eating to reduce their oxalic acid content. It is large consumption of oxalates over several months (re: comp diets) that you should be aware of. It makes good sense to vary your greens – a combination of high and low oxalate veggies to reduce overconsumption of potentially harmful oxalic acid, but also to provide a variety of calcium and other minerals contents that vary among different foods.
By Yvette Styner, Holistic Nutritionist & Dynamis Athlete