Kale

Kale is one of the most nutrient-dense foods in the supermarket. Rich in antioxidants, such as beta-carotene and vitamin C, it is also high in fiber and calcium, like other members of the cabbage family. Because autumn frosts give the hearty green such a deep sweetness, you'll want to eat it all winter long. Varieties to look for include curly kale and Tuscan kale (also called lacinato, cavolo nero, or dinosaur kale), which has darker, flatter leaves.

Health Benefits:  One cup of chopped kale contains 33 calories and 9% of the daily value of calcium, 206% of vitamin A, 134% of vitamin C, and a whopping 684% of vitamin K. It is also a good source of minerals copper, potassium, iron, manganese, and phosphorus. Kale’s health benefits are primarily linked to the high concentration and excellent source of antioxidant vitamins A, C, and K -- and sulphur-containing phytonutrients. Carotenoids and flavonoids are the specific types of antioxidants associated with many of the anti-cancer health benefits. Kale is also rich in the eye-health promoting lutein and zeaxanthin compounds.

Beyond antioxidants, the fiber content of cruciferous kale binds bile acids and helps lower blood cholesterol levels and reduce the risk of heart disease, especially when kale is cooked instead of raw. Eating a diet rich in the powerful antioxidant vitamin K can reduce the overall risk of developing or dying from cancer, according to a study in the American Journal of Clinical Nutrition. Vitamin K is abundant in kale but also found in parsley, spinach, collard greens, and animal products such as cheese.

Kale might be a powerhouse of nutrients but is also contains oxalates, naturally occurring substances that can interfere with the absorption of calcium. Avoid eating calcium-rich foods like dairy at the same time as kale to prevent any problems.

Buying and Storing:  Choose deeply colored bunches with springy leaves. Small, tender leaves cook more quickly, but larger ones are great for braising. Store kale in a plastic bag in the coldest spot of your refrigerator for up to 3 days.

How to Use:  Discard the stems and center ribs before washing unless kale is young and very tender. Kale is the backbone of classic soups such as minestrone; it also pairs well with potatoes, white beans, pasta with cheese, or smoked meats like sausage or bacon. The green lends itself to a variety of preparations. Tuscan kale, in particular, turns meltingly tender when cooked long and slow. A quick saute with garlic and red-pepper flakes is great for weeknights, or toss torn leaves with olive oil and salt and bake for crispy kale "chips."