- 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 nutrition and healthy eating guide, 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, Katherine 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 wellness nutrition at Mayo Clinic in Rochester, Minn., and nutrition education related to weight management and practical applications of nutrition-related lifestyle changes.
Other areas of interest include food and nutrition for all life stages, active lifestyles and the culinary arts.
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 (31)
- Phenylalanine in diet soda: Is it harmful?
- Diet soda: Is it bad for you?
- Stevia: Can it help with weight control?
- see all in Nutrition basics
Healthy diets (10)
- Canola oil: Does it contain toxins?
- Butter vs. margarine: Which is better for my heart?
- Detox diets: Do they work?
- see all in Healthy diets
Healthy cooking (7)
- Moldy cheese: Is it OK to eat?
- Food poisoning: How long can you safely keep leftovers?
- When the heat is on, which oil should you use?
- see all in Healthy cooking
Healthy menus and shopping strategies (8)
- Calories in sushi: What are the low-cal options?
- Sodium nitrate in meat: Heart disease risk factor?
- What is BPA? Should I be worried about it?
- see all in Healthy menus and shopping strategies
Nutritional supplements (18)
- What is wheatgrass — And why is it in my drink?
- Do the benefits of vitamin C include improved mood?
- Prenatal vitamins: OK for women who aren't pregnant?
- see all in Nutritional supplements
Free
E-newsletter
Subscribe to Housecall
Our weekly general interest
e-newsletter keeps you up to date
on a wide variety of health topics.
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? Is it safe?
Answer
from Katherine Zeratsky, R.D., L.D.
The leaves and twigs of the yerba mate plant are dried, typically over a fire, and steeped in hot water to make an herbal tea. This beverage, commonly known simply as mate, is popular in parts of South America. Like black tea, yerba mate contains caffeine, which is a stimulant.
In the U.S. 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 help treat headaches and various other conditions. There's no definitive evidence that these claims are valid.
Yerba mate isn't likely to pose a risk for healthy adults who occasionally drink it. However, some studies indicate that people who drink large amounts of yerba mate over prolonged periods may be at increased risk of some types of cancer, such as cancer of the mouth, esophagus and lungs. Smoking in combination with yerba mate seems to greatly increase the cancer risk.
One possible explanation is that mate contains polycyclic aromatic hydrocarbons (PAHs), which are known to be carcinogenic. (Tobacco smoke and grilled meat also contain PAHs.) More investigation needs to be done into the safety and side effects of mate.
If yerba mate is your cup of tea, enjoy it in moderation. But, as always, check with your doctor before trying any herbal product.
Next questionWhat are functional foods?
- Mate. Natural Medicines Comprehensive Database. http://www.naturaldatabase.com. Accessed Sept. 28, 2012.
- Heck CI, et al. Yerba mate tea (Ilex paraguariensis): A comprehensive review on chemistry, health implications, and technological considerations. Journal of Food and Science. 2007;72:R138.
- Kamangar F, et al. High levels of carcinogenic polycyclic aromatic hydrocarbons in mate drinks. Cancer Epidemiology Biomarkers Prevention. 2008;17:1262.
- Zeratsky KA (expert opinion). Mayo Clinic, Rochester, Minn. Sept. 28, 2012.
Find Mayo Clinic on