“Spinach is full of pleasant surprises [and a top-ten "power food"]. It’s a natural source of iron… and a rich non-dairy source of calcium.“
Those sentences appear in The Sonoma Diet, penned by Registered Dietitian Connie Guttersen.
I find it incomprehensible that a Registered Dietitian can make such an elementary mistake.
Although spinach offers plenty of vitamins, antioxidants, and phytonutrients, it is not a rich source of iron or calcium.
Unlike other leafy greens (i.e.: bok choy, broccoli, mustard greens, and kale) which are very good sources of both those minerals, spinach is loaded with compouds known as oxalates.
Oxalates bind to iron and calcium, significantly decreasing absorption of those minerals in our digestive systems.
Consider the following:
- A half cup of cooked Chinese cabbage delivers as much calcium as a cup of milk
- One and a quarter cups of cooked bok choy deliver as much calcium as a cup of milk
- Eight cups of cooked spinach deliver as much calcium as a cup of milk
What makes this tricky is that the figures presented for spinach in terms of iron and calcium content do not take into account decreased absorption. Therefore, you will see that a half cup of cooked spinach “provides” 115 milligrams of calcium (11% of the Daily Value). Sadly, we only absorb 10 to 15% of that amount.
Please share this tidbit with as many people as you can. I am continually amazed by the amount of health professionals (dietitians, doctors, and educators) who keep this myth alive.