Spinach can be eaten raw in salads, steamed or added to stir-frys and soups. Low in calories but high in vitamins, minerals and fiber, it is a versatile addition to a healthy diet. In rare cases, consuming excessive amounts of spinach can lead to kidney stones, issues with iron absorption and gastrointestinal difficulties. Maintaining a balanced, varied diet will help you avoid these problems.
Nutrition in Spinach
A cup of cooked and drained spinach offers 41 calories and 4.3 g of fiber. Its high mineral content includes 245 mg of calcium, 6.43 mg of iron, 157 mg of magnesium, 101 mg of phosphorous and 839 mg of potassium. It also contains 17.6 mg of vitamins C, 263 mcg of folate, 11,319 mcg of beta-carotene, 35.5 mg of choline, 20,354 mcg of lutein and zeaxanthin and 18,866 IU of vitamin A.
Spinach contains a naturally occurring substance called oxalate. In rare cases, eating extreme amounts of oxalate-rich foods like spinach, nuts, pepper and rhubarb can lead to a condition called hyperoxaluria, in which oxalate crystals combine with calcium in the kidney and form kidney stones. Kidney stones can cause sharp pain in the lower back, genitals or inner thigh, urinary problems, nausea and abdominal bloating. If you notice these symptoms, see your doctor.
Although spinach contains high levels of iron, plant-based iron – or nonheme iron – can be difficult for the body to absorb. The oxalate in spinach can combine with iron, interfering with the body’s ability to absorb it. Try eating spinach with citrus fruit or juice, since vitamin C can help counteract this effect and increase absorption. Calcium-rich foods and whole grains can also keep the body from absorbing nonheme iron, so it may help to avoid eating these foods at the same time as spinach.
Dietary fiber like the fiber found in spinach is essential to healthy digestion, but when eaten in excess, it can cause gastrointestinal distress, including gas, cramps, bloating, constipation or diarrhea. If you experience any of these symptoms after eating spinach, introduce it to your diet more slowly. Eat smaller portions until your digestive bacteria become accustomed to the additional fiber. If your symptoms persist, speak with your doctor.
- Centers for Disease Control and Prevention: Spinach
- U.S. Department of Agriculture National Nutrient Database for Standard Reference: Spinach, Cooked, Boiled, Drained, Without Salt
- Medline Plus: Fiber
- University of Maryland Medical Center; Iron; Steven D. Ehrlich; 2009
- Cedars-Sinai: Health Conditions – Kidney Stones