Cooking spinach increases the amount of oxalic acid.
Oxalic acid prevents the absorbtion of calcium. Even raw spinach contains a considerable amount of oxalic acid, but my research shows that cooked spinach has far more.
Oxalic acid is a main cause of
kidney stones (and a variety of other problems), so be sure to keep an eye on spinach consumption (ESPECIALLY cooked spinach).
"Another cause (of kidney stones) is the excess consumption of vitamin C and oxalic acid which caused the the excretion of oxalate. This is present in cooked spinach (not as much in raw). Animal protein is also strongly associated with oxalate absorption."
http://www.naturallydirect.net/kidney-problem.htm
The link (above) certainly is NOT the be-all-end-all of "truth"...but if you do a search combining "cooked spinach" and "oxalic acid" you'll find a LOT of VERY good information about how foods that are high in oxalic acid can contribute to calcium deficiency, kidney stones, etc.
I just did a quick search and found this, too (it's much more explanatory & complete):
http://www.bellaonline.com/ArticlesP/art19856.asp
*A diet high in oxalic acid (almonds, beet greens, cashews, chard, cocoa/chocolate, kale, rhubarb, soybeans and cooked spinach) interferes with calcium absorption.
And by the way, e coli is NOT a problem for those with strong alkaline terrains. We have e coli in our body all the time, it's only an "overgrowth" of e coli that causes symptoms or harm (just the same as yeast). When the body is truly & thoroughly alkaline, e coli cannot multiple to a point of danger or problem, because they cannot live. (Please note: "truly & thoroughly" alkaline does NOT mean testing "alkaline" on pH test strips after drinking a few alkalizing cocktails for a few days or weeks...I mean a complete state of alkalinity, which can only be achieved by flushing & cleansing our organs, eliminating all toxins (possible) from our diet, having strong 'flow' and circulation, combined with a diet high in alkaline, raw fruits & vegetables,...generally without meat or dairy in any significant amount). When that is achieved, one is a virtual "Superman"...but until that point of alkalinity is reached, there is still danger associated with ingesting mass quantities of e coli.
Blessings always,
Unyquity