[Modified3019]

Yeah oxalic acid plus calcium is calcium oxalate, aka the most common form of kidney stones. Some people also seem to be sensitive to oxalates for whatever reason, and find improvements in health when broadly removing sources from their diets.

The trick is to bind the oxalates before they get absorbed in the body and require removal. So making things like traditional creamed spinach (or other things like turnip or collard greens) removes the potential hazard from chronic intake.

Incidentally the whey portion of dairy also seems to chelate the form of vitamin B12 found in plants, making it much more bioavailable. The casein portion of dairy doesn’t seem to have this same effect.

It’s fascinating to see how the preparation for so many traditional foods basically mitigates the sources of low level toxicity issues while increasing nutrient update, when as a “modern” person I tend to look at it from the perspective of taste.