The benefits of cooking greens

Cooking greens — kale, Swiss chard and collard, beet, turnip and mustard greens — are packed with vitamins, minerals, fibre and an array of phytochemicals that may reduce heart disease risk, eye diseases and certain cancers. Read on to learn how to maximize their benefits.

1. Beta-carotene: Greens are rich sources of this antioxidant, which may help strengthen the body's defence system against harmful free-radical compounds. Kale has the most, with 5.8 milligrams per 250 grams (one cup) of cooked.
2. Calcium: Although this mineral is found in greens, some greens, such as Swiss chard and beet greens, contain compounds called oxalates, which prevent calcium from being properly absorbed. If you are prone to kidney stones or gout, avoid foods high in oxalates.
3. Chlorophyll: This plant pigment may help to block the damaging changes that convert healthy cells to pre-cancerous cells.
4. Folate: Cooking greens are a good source of this important B vitamin, which helps to ward off certain birth defects, cancer and heart disease. Collards and turnip greens are the best for folate content.
5. Indoles: Indoles are thought to help protect against the risk for hormone-related cancers by blocking the action of estrogen.
6. Isothiocyanates: Partially responsible for the pungency of some leafy greens, these phytochemicals are thought to help protect against hormone-dependent cancers. These compounds are also believed to inhibit environmental carcinogens.
7. Lutein and zeaxanthin: These carotenoids are linked to the prevention of macular degeneration. Kale is an extremely rich source of these phytochemicals; collard greens are also a good source.
8. Sulforaphane: This phytochemical may help prevent harmful carcinogens from initiating cancer.
9. Vitamin K: Found in huge amounts in cooking greens, this bone-building, anti-clotting vitamin may interfere with blood-thinning medications.

To enhance the bioavailability of beta-carotene in cooking greens, cook them with a small amount of olive oil. If you do cook greens in water, which can diminish folate levels, try to use the cooking water in the recipe.

• Combine chopped sautéed kale with ricotta and grated Parmesan cheese and use as a filling for lasagna or manicotti.
• Make a green bruschetta. Finely chop cooking greens and sauté with garlic in olive oil until melt-in-your-mouth tender. Use as a topping for thick slices of toasted Italian bread.
• Cook assorted greens in seasoned water with some olive oil and eat both the greens and their cooking liquid over slabs of cornbread.
• Chop and steam cooking greens, then fold into garlicky mashed potatoes.
• In a traditional Italian dessert tart — crostata di verdure — finely chopped, cooked greens, such as Swiss chard or kale, are combined with a sweetened custard and used as the tart's filling.
• Add chopped, cooked greens to your favourite meatball or meatloaf mixture.