- With Mayo Clinic nutritionist
Katherine Zeratsky, R.D., L.D.
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Katherine Zeratsky, R.D., L.D.
Katherine Zeratsky, R.D., L.D.
As a specialty editor for the Food & Nutrition Center, Katherine Zeratsky helps you sort through the facts and figures, the fads and the hype to learn more about nutrition and diet.
A Marinette, Wis., native, she is certified in dietetics by the state of Minnesota and the American Dietetic Association. She has been with Mayo Clinic since 1999.
She is active in nutrition-related curriculum and course development in pediatrics at Mayo Clinic Rochester and nutrition education related to the physiology and recommended intakes for premature infants.
Other areas of interest include breast milk and formula safety, neonatal feeding, and nutrition for breast-feeding mothers.
She graduated from the University of Wisconsin-Madison, served a dietetic internship at the University of Iowa Hospitals and Clinics, and worked as a registered dietitian and health risk counselor at ThedaCare of Appleton, Wis., before joining the Mayo Clinic staff.
Nutrition basics (21)
- Diet soda: Is it bad for you?
- Nutrition rating system: What's behind the new food labels?
- Underweight? See how to add pounds healthfully
- see all in Nutrition basics
Healthy diets (8)
- Diverticulitis diet: Can certain foods trigger an attack?
- Butter vs. margarine: Which is better for my heart?
- Detox diets: Do they offer any health benefits?
- see all in Healthy diets
Healthy cooking (10)
- Canned pumpkin: Better than fresh?
- Lentils: How do I cook with them?
- Food poisoning: How long can you safely keep leftovers?
- see all in Healthy cooking
Healthy menus and shopping strategies (6)
- Sea salt vs. table salt: Which is healthier?
- White whole-wheat bread: Is it nutritious?
- What is BPA? Should I be worried about it?
- see all in Healthy menus and shopping strategies
Nutritional supplements (15)
- Vitamin D toxicity: What if you get too much?
- Prenatal vitamins: OK for women who aren't pregnant?
- Fiber supplements: Are they safe to take every day?
- see all in Nutritional supplements
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Question
Microwaving plastic: Does it release dioxins?
Does microwaving plastic food containers cause them to leach dioxins into the food?
Answer
from Katherine Zeratsky, R.D., L.D.
Dioxins are cancer-causing substances most often found in soil, water and animal fat. Brush fires and forest fires naturally release dioxins into the air. So, too, does the uncontrolled burning of household trash. Certain chemical and industrial processes also may form small amounts of dioxins. Although stories have circulated for years that freezing or microwaving plastic food containers or wraps causes them to release dioxins, this isn't thought to be true.
Still, it's important to follow general safety guidelines when you're heating food in the microwave. For example:
- Use microwave-safe containers. Use containers or wraps specifically labeled as "microwave-safe." Don't use margarine tubs, carryout containers, or paper or plastic grocery bags.
- Check product labels. When you heat packaged foods, follow the microwave instructions printed on the label. If instructions aren't given, transfer the food to a plate or container that you know is microwave-safe.
- Don't allow plastic wrap to touch the food. Leave a small gap between the plastic wrap and the food while it's being heated.
Thanksgiving turkey: Can you cook it frozen?
- Questions and answers about dioxins. Food and Drug Administration. http://www.cfsan.fda.gov/~lrd/dioxinqa.html#g2. Accessed Oct. 30, 2008.
- Cooking safely in the microwave oven. USDA Food Safety and Inspection Service. http://www.fsis.usda.gov/Fact_Sheets/Cooking_Safely_in_the_Microwave/index.asp. Accessed Oct. 30, 2008.
