Popeye was definitely on to something. Spinach is a super food loaded with tons of nutrients in a low calorie package.
Dark leafy greens like spinach are important for skin and hair, bone health, and provide protein, iron, vitamins and minerals.
The possible health benefits of consuming spinach include improving blood glucose control in diabetics, lowering the risk of cancer, lowering blood pressure, improving bone health, lowering the risk of developing asthma and more.
This MNT Knowledge Center article is part of a collection of features on the health benefits of popular foods, all written and reviewed by our qualified nutritionist.
Possible health benefits of spinach
Diabetes management: spinach contains an antioxidant known as alpha-lipoic acid, which has been shown to lower glucose levels, increase insulin sensitivity and prevent oxidative stress-induced changes in patients with diabetes. Studies on alpha-lipoic acid have also shown decreases in peripheral neuropathy and/or autonomic neuropathy in diabetics.1
Of note, most studies have used intra-venous alpha-lipoic acid and it is unsure whether oral supplementation would elicit the same benefits.1
Cancer prevention: Spinach and other green vegetables contain chlorophyll which has shown to be effective at blocking the carcinogenic effects of heterocyclic amines which are generated when grilling foods at a high temperature.2
Asthma prevention: The risks for developing asthma are lower in people who consume a high amount of certain nutrients. One of these nutrients is beta-carotene, of which spinach is an excellent source. Apricots, broccoli, cantaloupe, pumpkin and carrots are also rich sources of beta-carotene.3
Lowering blood pressure: because of its high potassium content, spinach is recommended to those with high blood pressure to negate the effects of sodium in the body. A low potassium intake may be just as big of a risk factor in developing high blood pressure as a high sodium intake.4
Other high potassium foods include potatoes, tomatoes, lima beans and oranges.
Bone health: Low intakes of vitamin K have been associated with a higher risk for bone fracture. Adequate vitamin K consumption is important for good health, as it acts as a modifier of bone matrix proteins, improves calcium absorption and may reduce urinary excretion of calcium.5
Promotes regularity: Spinach is high in fiber and water content, both of which help to prevent constipation and promote a healthy digestive tract.
Healthy skin and hair: Spinach is high in vitamin A, which is necessary for sebum production to keep hair moisturized. Vitamin A is also necessary for the growth of all bodily tissues, including skin and hair. Spinach and other leafy greens high in vitamin C are imperative for the building and maintenance of collagen, which provides structure to skin and hair.
Iron-deficiency is a common cause of hair loss, which can be prevented by an adequate intake of iron-rich foods, like spinach.
Nutritional breakdown of spinach
One cup of raw spinach contains 27 calories, 0.86 grams of protein, 30 milligrams of calcium, 0.81 grams of iron, 24 milligrams of magnesium, 167 milligrams of potassium, 2813 IUs of Vitamin A and 58 micrograms of folate.
Most of the calories in spinach come from protein.
Spinach is one of the best sources of dietary potassium, weighing in at 839mg per cup (cooked). To compare, one cup of banana has about 539mg of potassium.
A lack of iron in your diet can effect how efficiently your body uses energy. Spinach is a great non-heme source of iron, along with lentils, tuna and eggs.
Spinach contains approximately 250mg of calcium per cup (cooked), however it is less easily absorbed than calcium from sources like dairy products. Spinach has a high oxalate content, which binds to calcium deeming it unavailable for use in our bodies.
When it's all said and done, our bodies can only absorb about 5% of the calcium in spinach (about 12.5mg per cup) whereas the absorption rate from calcium in milk is about 28% (300mg of calcium in one cup of milk at a bioavailability level of 28% would provide 84 mg per cup).
Spinach is also one of the best sources of dietary magnesium, which is necessary for energy metabolism, maintaining muscle and nerve function, heart rhythm, a healthy immune system and maintaining blood pressure. Magnesium also plays a part in hundreds more biochemical reactions that occur in the body.
Those with digestive disorders, alcoholic, older adults and individuals taking medications such as antibiotics and diuretics are more likely to have a magnesium deficiency and should consume more leafy greens.
Spinach also contains vitamin K, fiber, phosphorus and thiamine.
On the next page we look at ways in which to incorporate more spinach into your diet and precautions associated with consuming spinach.