Study of the Effects of Yerba Mate on Cardiometabolic Health

The goal of this clinical trial is to learn if consuming a beverage prepared with yerba mate leaves helps to improve blood lipid levels in persons at high cardiovascular risk. It will also learn about the effects of this beverage, widely consumed in South America, on other cardiometabolic biomarkers like blood glucose levels, inflammation, or weight control. The main questions it aims to answer are: Does daily consumption of a yerba mate tea reduce the blood lipid levels in hypercholesterolemic persons? May healthy persons also benefit from the consumption of yerba mate tea? Researchers will compare yerba mate to a control drink (isotonic drink or water, free of polyphenols and caffeine) to see if yerba mate tea helps to reduce blood cholesterol in hypercholesterolemic persons. Participants will: Drink 3 cups of yerba mate tea or an isotonic drink every day for 2 months, then change to the other drink during another 2 months. Visit the clinic at the beginning and end of each 2-month period for checkups and tests Refraing from consuming coffee and some foods during the study. Complete a dietary questionnaire during 3 days before each visit to the clinic.

This is a randomized, crossover, control study in healthy and hypercholesterolemic free-living to assess the effect of yerba mate on different outcomes related to cardiovascular health. After a 2-week run-in period, participants will be randomly allocated to the first 8-weeks intervention with yerba mate or the control drink. After a 3-week wash-out, they will change to consume during 8 weeks the other drink. A nurse will collect a fasting blood sample at the beginning and end of each intervention stage. Blood pressure and anthropometric parameters will be measured. A 72-h dietary record will be completed by participants before each visit to the Human Nutrition Unit (HNU) at the Institute of Food Science, Technology and Nutrition (ICTAN-CSIC). During the study, participants will refrain from consuming coffee, cocoa, tea, and caffeine-containing drinks. Other foods rich in certain polyphenols (i.e. hydroxycinnamic acids) will also be restricted. Blood samples will be used to measure different biomarkers of relevance in cardiometabolic health, as listed in the Outcomes section.