Spinach is packed full of healthy nutrients! In fact, green leafy vegetables like spinach provide more nutrition per calorie than any other food. One cup of fresh spinach contains almost 200% of the daily value of vitamin K and, because it cooks down so much, one cup of cooked spinach has over 1000% of the daily value of vitamin K. Vitamin K is vital for strong bones – it prevents their breakdown and activates protein in bone tissue. Vitamin K also activates osteocalcin, which anchors calcium inside our skeletons. Spinach is an excellent source of other bone-building nutrients like calcium and magnesium. One caveat, however: people who are taking the blood-thinning medication Coumadin need to be careful to get the recommended daily amount of Vitamin K without going overboard with it, as that will interfere with the effectiveness of the drug.
Some of you may be worried about the oxalic acid in spinach. There is a plethora of articles on the web that highlight the ability of oxalic acid to bind with calcium and thus make calcium unavailable to the body, though many references are either from inherently unreliable sources, or they to parrot material they scarcely understand. There is little hard data showing that oxalic acid reduces dietary calcium in an amount sufficient enough to affect calcium levels.
In fact, the National Institute of Health states that “For people who eat a variety of foods, these interactions probably have little or no nutritional consequence and, furthermore, are accounted for in the overall calcium DRIs [Dietary Reference Intakes], which take absorption into account.”
Spinach is an excellent source of vitamins C and A, both terrific antioxidants needed to reduce free radicals and to help prevent cholesterol from building up on the walls of arteries. How about folate and magnesium? Spinach contains lots of these nutrients, offering yet more protection against heart attack and stroke. Because of certain peptides contained in spinach, eating it daily may help reduce high blood pressure. Are you convinced yet? The list goes on and on.
Spinach is also high in manganese, iron, vitamin B2, B3 and B6, potassium, tryptophan, vitamin E, copper, zinc, and selenium. While the plant-based iron that spinach contains has a much lower absorption percentage (3-8%) than iron found in food from an animal (23%), the iron absorption can be increased by as much as 200-300% by eating or drinking large amounts of vitamin C with it. In addition to all of these nutrients, researchers have found at least 13 phytonutrient flavonoids in spinach which act as antioxidants and anti-cancer agents.
Spinach does have a downside, however. It is one of the “dirty dozen”: foods high in pesticide levels. This problem is easy to resolve: just make sure to choose an organic brand. It’s not that much more expensive. I buy the large 1 lb. container of organic spinach in the Earthbound brand from Costco or Marc’s (a local store here in Cleveland, OH) for $3.99, or a large bag at any other grocery store. This is fairly easy to use up, especially if you cook some of it.
The moral of this story is to eat lots of spinach! Check out July’s 2010’s Healthy Challenge.