- 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
Mayo Clinic Health Manager
Get free personalized health guidance for you and your family.
Get Started
About our e-newsletters
- Free e-newsletters
- Mayo Clinic expertise
- We do not share your e-mail address
Housecall, our weekly general-interest e-newsletter, keeps you up to date on a wide variety of health topics with timely, reliable, practical information, recipes, blogs, questions and answers with Mayo Clinic experts and more. Our biweekly topic-specific e-newsletters also include blogs, questions and answers with Mayo Clinic experts, and other useful information that will help you manage your health.
Housecall Archives
Mayo Clinic Housecall
Stay up to date on the latest health information.
What you get
- Free weekly e-newsletter
- Mayo Clinic expertise
- Recipes, tools and other helpful information
- We do not share your e-mail address
Question
Yerba mate: Is it safe to drink?
A friend suggested that I try yerba mate tea to boost my energy. What is yerba mate? And what do researchers know about it?
Answer
from Katherine Zeratsky, R.D., L.D.
Yerba mate is a tropical plant. Yerba mate leaves and twigs can be steeped in hot water to make a tea-like beverage known simply as mate. In fact, yerba mate is widely available in health food stores and online. Proponents of yerba mate say that it can relieve fatigue, promote weight loss, ease depression and headaches, and help treat various other conditions. However, yerba mate contains enough caffeine to raise your heart rate and blood pressure, as well as cause fluctuations in your blood sugar level. Even more concerning is a possible association with cancer. Some studies indicate that prolonged use of yerba mate increases the risk of various types of cancer, including cancer of the mouth, esophagus and lungs. Smoking in combination with yerba mate seems to greatly increase the cancer risk. Until researchers know more about the risks, you may want to avoid yerba mate.
Next question
