PRESCRIPTIONS
Peculiar cooking method flaws study on microwaved veggies
By Amy Tousman
Q. I thought microwaving was a good way to retain nutrients in vegetables, but I recently read about a study saying that that this method "zaps beneficial antioxidants and nutrients right out of your food."
A. I recommend cooking vegetables in the microwave as a convenient, healthy option. When hearing about new studies, it is important to look at the details. The study you are referring was published in the November 2003 issue of the Journal of food Science and Agriculture. This well-publicized study had important flaws that most of the media never noticed.
The study compared several cooking methods including microwaving, pressure-cooking, boiling and steaming. The vegetable used in the study was broccoli. The researchers found that pressure-cooking, boiling and microwaving caused antioxidants to leak out of the vegetables and into the cooking water.
The results showed that the broccoli lost 74 to 97 percent of the three cancer-fighting antioxidants. The steamed vegetables lost up to 11 percent of these antioxidants.
Before jumping to any conclusions here, we need to look at how the broccoli was microwaved. Here is where the problem lies. One cup of raw chopped broccoli was microwaved in 2/3 of a cup of water. The vegetables were nuked at full power for 5 minutes.
I don't know about you, but when I microwave vegetables such as broccoli, I normally use only 1 or 2 tablespoons of water. I usually cook them just until they are tender-crisp, about 2 or 3 minutes.
In other words, these researchers used a lot more water than necessary and cooked the broccoli far too long. In fact, broccoli that is cooked for that long usually loses its nice color, turns mushy and develops an unpleasant taste.
All this study really shows is that using too much water and cooking vegetables for too long will cause them to lose much of their cancer-fighting antioxidants.
Contrary to this study, research done at the University of Illinois, soon to be published in the journal Phytochemistry, found that microwaving broccoli for 2 minutes in a little bit of water maintains nutrients as well as steaming.
Microwaving is a great way to preserve most vitamins, minerals, and antioxidants in foods because the food's exposure to heat and water is shorter than other cooking methods.
Amy Tousman is a registered dietitian with the Health Education Center of Straub Clinic and Hospital. Hawai'i experts in traditional medicine, naturopathic medicine and diet take turns writing the Prescriptions column.
Send your questions to: Prescriptions, Island Life, The Advertiser, P.O. Box 3110, Honolulu, HI 96802; fax 535-8170; e-mail islandlife@honoluluadvertiser.com. This column is not intended to provide medical advice.
