The Truth: It's complicated.
This nutrition myth isn’t so easy to break down into fact or fiction — the truth really depends on what type of vegetables you’re eating. I’ll outline both arguments, and help you decide how to prepare your daily dose of veggies. Take notes!
Don’t let raw foodies brainwash you. Yes, it is true that cooking vegetables can potentially destroy some of their vitamin content, but some of the other claims by raw-food devotees aren’t true. Some raw-food experts claim that raw veggies have more enzymes than cooked ones, but registered dietitians have stated that while heating foods above 188 degrees can deactivate certain plant enzymes, those enzymes that are lost are actually made to support the survival of plants — and are not essential to human health.
Cooking vegetables makes them easier to digest. Some people have a hard time breaking down raw vegetables in their gastrointestinal tract. Lightly cooking vegetables helps to break down the plants’ cell walls, making them easier to digest. If cooking your vegetables makes them easier for you to consume — by all means, cook away.
Cooking certain vegetables actually helps to boost their nutritional content. A great example of this is what happens when you cook tomatoes. Cooking tomatoes boosts their amount of lycopene, a powerful antioxidant that is believed to fight a variety of cancers (including prostate, colorectal, pancreatic, breast, lung, and endometrial). Another source of proof, a 2007 study from the Journal of Agricultural and Food Chemistry found that while boiling and steaming carrots, zucchini, and broccoli maintained their antioxidant compounds – steaming broccoli actually increased its content of glucosinolates, a group of plant compounds touted for their cancer-fighting abilities.
Don’t be afraid of the microwave. Many people think microwaving vegetables zaps all the nutritional benefits out of them. Think again. Much like steaming, microwaving veggies helps to preserve certain nutrients — in broccoli's case, it preserves 90 percent of its vitamin C content. Be sure to avoid overcooking broccoli and other cruciferous veggies (like brussels sprouts, cauliflower, kale, bok choy and others), though, because it could cause them to lose nutrients. You’ll know they’re overcooked when they’re mushy and start to stink. I like mine crunchy, like they’re raw, so I blanch my cruciferous veggies by throwing them into a pot of boiling water for two minutes, draining quickly, and then rinsing with ice-cold water. Give it a try if you like that “snap,” too.
The Bottom Line: We don’t eat nearly enough vegetables as we all should, so I’m certainly not going to yell at you if you are eating them, but choose to boil instead of blanch — or eat them raw. Just strive for five fruits and veggies each day and keep these prep facts in mind!