- With Mayo Clinic nutritionist
Katherine Zeratsky, R.D., L.D.
read biographyclose windowBiography of
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 (20)
- Water softeners: How much sodium do they add?
- Caffeine: Is it dehydrating or not?
- Coffee and health: What does the research say?
- 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?
- Canola oil: Does it contain toxins?
- see all in Healthy diets
Healthy cooking (10)
- Lentils: How do I cook with them?
- Food poisoning: How long can you safely keep leftovers?
- Canned pumpkin: Better than fresh?
- see all in Healthy cooking
Healthy menus and shopping strategies (6)
- Calories in sushi: What are the low-cal options?
- Vegetable juice: As good as whole vegetables?
- Buying beef? A guide to choosing the leanest cuts
- see all in Healthy menus and shopping strategies
Nutritional supplements (15)
- Vitamin water: Better than plain water?
- Ground flaxseed: Better than whole?
- Vitamin C: Can too much be harmful?
- see all in Nutritional supplements
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Question
Canola oil: Does it contain toxins?
I read an article on the Internet that said canola oil contains toxins that are harmful to humans. Is this true?
Answer
from Katherine Zeratsky, R.D., L.D.
Health concerns about canola oil that are being circulated on the Internet are unfounded.
Misinformation about the safety of canola oil may stem from the fact that, years ago, oil was produced from the rapeseed plant. Rapeseed oil contains very high levels — 30 percent to 60 percent — of erucic acid, a compound that in large amounts can be toxic to humans. The canola plant was developed by natural cross-breeding from the rapeseed plant in the early 1970s. Canola oil is produced from canola plants, not rapeseed plants.
Canola plants have very low levels of erucic acid. According to the Food and Drug Administration (FDA), canola oil contains erucic acid levels in the range of 0.3 percent to 1.2 percent. This is well below the 2 percent limit set by the FDA.
Canola oil is very low in saturated fat and has a very high proportion of monounsaturated fat. So, it's a healthy and safe choice when it comes to oils.
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