Broccoli contains vitamins (K, A, and B), antioxidants, digestion-improving fibre, protein, and more. But how you cook broccoli can make a big difference in how nutritious it is.
Studies suggest that steaming your broccoli for 3-4 minutes until it turns a bright green will boost its cancer-fighting compounds. Broccoli and other cruciferous vegetables are a good source of sulforaphane, a phytochemical (naturally occurring plant compound) that has shown strong anti-cancer properties in lab studies.
A 2009 study found that broccoli retained the most nutrients when it was steamed compared to when it was boiled (or microwaved or stir-fried). Similarly, another study that examined other types of veggies found that they lost about 50% of their antioxidants when boiled as opposed to steamed.
When broccoli is boiled, the hot water can leach some of the vitamins and minerals out of it. (If you’re not drinking this water, you’re missing out on those nutrients.) Steamed broccoli doesn’t come into contact with water so it retains more of those healthy antioxidants.