04-21-09 RODALE NEWS, EMMAUS, PA—Eating as many fresh, whole vegetables as you can helps both us and our environment in a number of ways. Vegetables tend to come with less packaging than processed food, meaning less refuse is added to the waste stream. If the veggies are USDA certified organic, they’re grown by methods that add carbon to our soil, rather than adding it to our atmosphere and contributing to global warming. If they’re grown locally, fewer fossil fuels are burned to deliver them to the store.
And the list of benefits that antioxidant nutrients in vegetables provide for your health is long, too. But a new study out of Spain reveals that how you treat each nutrient-rich vegetable during the cooking process determines how many health-boosting antioxidants make it to your plate. Spanish researchers recently took 20 common veggies and measured antioxidant content before and after preparing the veggies six different ways. The results varied, but as a general rule of thumb, griddling (that’s cooking on a flat metal surface with no oil) and microwave cooking maintained the highest antioxidant levels, according to the study published this month in the Journal of Food Science.
Here’s what you need to know about cooking your veggies for optimum nutrition.
1. Microwaving—When in doubt, microwave your veggies for maximum antioxidant preservation. Exception: Keep cauliflower out of the microwave; it loses more than 50 percent of its antioxidants if nuked.
2. Griddling—Beets, celery, onions, Swiss chard, and green beans cook particularly well on the griddle. Word of caution: Griddles are often coated in nonstick chemicals that make cooking and cleaning convenient, but may contain toxins linked to cancer. Shop for one without the coating, or use a thick frying pan with no oil.
3. Baking—It’s good for most veggies, with exceptions. Researchers baked veggies (at about 392 degrees Fahrenheit) and found that some of the antioxidant properties in garlic and peppers were significantly lowered in the oven.
4. Frying—This method is kind of middle-of-the-road when it comes to antioxidant loss. Zucchini’s antioxidant powers especially drop when fried.
5. Pressure cooking and boiling—Generally speaking, don’t use these methods if you want to retain antioxidants in your vegetables. “In short, water is not the cook’s best friend when it comes to preparing vegetables,” says lead researcher A.M. Jimenez-Monreal. Peas, cauliflower, and zucchini are particularly susceptible to losing nutrients through boiling.
A few other neat facts:
• Green beans, beets, and garlic kept their antioxidant levels after most cooking treatments.
• The antioxidant content of green beans, celery, and carrots actually increased with all cooking methods, except for boiling green beans.
• The artichoke was the only veggie to keep its high antioxidant level during all the cooking methods.