Spinach is low in carbs, but high in insoluble fiber. This type of fiber may have benefits for digestion. Spinach is an extremely nutrient-rich vegetable. It contains high amounts of carotenoids, vitamin C, vitamin K, folic acid, iron and calcium. Spinach contains many plant compounds that can improve health. These include lutein, kaempferol, nitrates, quercetin and zeaxanthin. Spinach has been shown to reduce oxidative stress. The antioxidants found in spinach may help fight aging and reduce the risk of cancer and diabetes.