Cookbooks in the 1800s advised cooking spinach for nearly half an hour, according to the University of Arizona College of Agriculture and Life Sciences. These days, tossing a bunch of raw spinach into a smoothie and tucking a handful of fresh leaves into a lunch wrap are all the rage. Although eating spinach raw is the best way to get the leafy green's plentiful nutrients, including vitamins C and K and folate, lightly cooking spinach makes its iron content more easily absorbed. Find a happy medium by cooking spinach quickly and without a lot of water.
Use quick-cooking methods like steaming, sauteing or microwaving. Spinach wilts easily and only needs a few minutes in the pan or steamer to be tender and delicious. However, you want to cook it long enough to break down a compound called oxalic acid, which inhibits iron absorption in the body.
Cook your spinach with a good source of vitamin C. Spinach is often touted as a rich plant source of iron, but that's a bit of a myth. Although it does contain a pretty good amount -- 100 grams of raw spinach contain about 3 milligrams, close to 17 percent of an adult woman's daily recommended intake -- it also contains absorption-inhibiting oxalic acid. Vitamin C, or ascorbic acid, improves your body's ability to absorb iron from plant foods. Squeeze fresh lemon juice over sauteed spinach or throw mandarin orange slices into a stir-fry with spinach and chunks of chicken breast.
Avoid cooking methods that cause the spinach to come into direct contact with water, such as boiling. Although this won't greatly affect the iron content, it will reduce the content of water-soluble nutrients like vitamins C and the B vitamins, which can be leached into the water.
- Saute your spinach with a small amount of oil to improve your body's absorption of the fat-soluble vitamins A and K.
Jody Braverman is a professional writer and editor based in Atlanta. She studied creative writing at the American University of Paris and received a Bachelor of Arts in English from the University of Maryland. She also received personal trainer certification from NASM and her 200-hour yoga teacher certification from YogaWorks.